Concealed carry or carrying a concealed weapon (CCW), is the practice of carrying a weapon (such as a handgun) in public in a concealed manner, either on one's person or in close proximity. Not all weapons that fall under CCW laws are lethal. For example, in Florida, carrying pepper spray in more than a specified volume (2 oz.) of chemical requires a CCW permit, whereas everyone may legally carry a smaller, “self-defense chemical spray” device hidden on his person without a CCW permit.   As of 2018 [update] there have been 17.25 million concealed weapon permits issued in the United States. 
There is no federal statutory law concerning the issuance of concealed-carry permits. All 50 states have passed laws allowing qualified individuals to carry certain concealed firearms in public, either without a permit or after obtaining a permit from a designated government authority at the state and/or local level; however, there are still many states that, though they have passed concealed carry permit laws, do not issue permits or make it extremely difficult to obtain one.
A comprehensive 2004 literature review by the National Academy of Sciences concluded that there was no evidence that concealed carry either increases or reduces violent crime; some individual studies suggest that CCW reduces violent crime; others suggest that it increases violent crime. 
- 1 History
2 State laws
- 2.1 Permitting policies
- 2.2 Training requirements
- 2.3 Reciprocity
- 2.4 Restricted premises
- 2.5 "Opt-out" statutes ("gun-free zones")
- 2.6 Brandishing and printing
- 3 Federal law
- 4 Legal issues
- 5 Effect on violent crime
- 6 See also
- 7 References
- 8 Further reading
- 9 External links
Concealed weapons bans were passed in Kentucky and Louisiana in 1813. (In those days open carry of weapons for self-defense was considered acceptable; concealed carry was denounced as the practice of criminals.) By 1859, Indiana, Tennessee, Virginia, Alabama, and Ohio had followed suit.  By the end of the nineteenth century, similar laws were passed in places such as Texas, Florida, and Oklahoma, which protected some gun rights in their state constitutions.  Before the mid 1900s, most U.S. states had passed concealed carry laws rather than banning weapons completely.  Until the late 1990s, many Southern states were either "No-Issue" or "Restrictive May-Issue". Since then, these states have largely enacted "Shall-Issue" licensing laws, with numerous states legalizing " Unrestricted concealed carry".
Regulations differ widely by state, with most states currently maintaining a " Shall-Issue" policy. As recently as the mid-'90s most states were no-issue or may-issue, but over the past 30 years states have consistently migrated to less restrictive alternatives.[ citation needed]
There is currently a circuit split between several federal circuit courts regarding the standards for issuance of permits and the right to carry weapons outside the home. The 9th and 3rd circuits have ruled in favor of may-issue permitting policies, while the 7th and D.C. circuits have ruled that states are required to implement shall-issue policies, because the right to carry weapons extends outside the home.  
The Federal Gun Free School Zones Act limits where an unlicensed person may carry; carry of a weapon, openly or concealed, within 1,000 feet (300 m) of a school zone is prohibited, with exceptions granted in the Federal law to holders of valid State-issued weapons permits (State laws may reassert the illegality of school zone carry by license holders), and under LEOSA to current and honorably retired law enforcement officers (regardless of permit, usually trumping State law).
When in contact with an officer, some states require you to inform that officer that you are carrying a handgun.   For detailed information on individual states' permitting policies, see Gun laws in the United States by state.
- Unrestricted jurisdiction: one in which a permit is not required to carry a concealed handgun
- Shall-issue jurisdiction: one that requires a license to carry a concealed handgun, but where the granting of such licenses is subject only to meeting determinate criteria laid out in the law; the granting authority has no discretion in the awarding of the licenses, and there is no requirement of the applicant to demonstrate "good cause"
- May-issue jurisdiction: one that requires a permit to carry a concealed handgun, and where the granting of such permits is partially at the discretion of local authorities (frequently the sheriff's department or police)
- No-issue jurisdiction: one that – with very limited exceptions – does not allow any private citizen to carry a concealed handgun in public
|Permit Reciprocity ||Disputed|
|Alaska||For reciprocity purposes||Yes|
|Arizona||For reciprocity purposes||Yes|
|Arkansas||||For reciprocity purposes||Yes|
|California||In practice in 35 out of 58 counties as of January 2018; cities within those counties may be stricter. ||In practice in 12 of 58 Counties as of January 2018, cities within those counties may be more lenient. ||No|
|Colorado||Partial (33 states);
Resident permits only
|Connecticut||In practice ||No|
|Delaware||Rarely issued||Partial (21 states)|
|District of Columbia||Briefly from July 27, 2015 – July 29, 2015. See below for details.||||No|
|Florida||Partial (35 states);
Resident permits only
|Georgia||Partial (32 states)|
|Hawaii||In practice ||No|
|Idaho||Idaho residents 21 years or older only.||For reciprocity purposes||Yes|
|Illinois||Unloaded and enclosed in a case, firearm carrying box, shipping box, or other container     ||   ||Only for residents of Arkansas, Mississippi, Texas and Virginia. ||Vehicle carry only|
|Kansas||For reciprocity purposes||Yes|
|Louisiana||Partial (37 states)|
|Maine||Duty to inform if carrying concealed without permit.||For reciprocity purposes||Partial (27 states);
Resident permits only
|Maryland||In practice ||Rarely issued ||No|
|Massachusetts||In practice in some cities/counties||Rarely issued||No|
Resident permits only
|Minnesota||Partial (15 states)|
|Mississippi|| purse, handbag, satchel, other similar bag or briefcase or fully enclosed case. Only if carried in a belt/shoulder holster, sheath,||For reciprocity purposes, or to carry concealed without a holster, in an ankle holster, or using any other method not covered by the law's exception.||Yes|
|Missouri||For reciprocity purposes and open carry in localities where restricted.||Yes|
|Montana||Outside of city limits.||Partial (43 states)|
|Nebraska||Partial (38 states)|
|Nevada||Partial (30 states)|
|New Hampshire||For reciprocity purposes.||Partial (28 states);
Resident permits only
|New Jersey||In practice  ||Rarely issued  ||No|
|New Mexico||Unloaded.||Partial (24 states)|
|New York||In practice in some cities/counties, e.g. NYC ||No|
|North Dakota||North Dakota residents only. Duty to inform if carrying concealed without permit.||For reciprocity purposes and open carry.||Partial (39 states)|
|Northern Mariana Islands||No|
|Oklahoma||Residents of permitless carry
states with valid ID.
|Oregon||||Only for residents of CA, ID, NV, and WA.||No|
|Pennsylvania||Partial (29 states);
Resident permits only
|Puerto Rico||From June 20, 2015 to October 31, 2016.||In practice ||Has reciprocity law, but does not recognize any other state permits|
|Rhode Island||Local permits||Attorney General issued permits||In practice for permits issued by the Attorney General's office||Rarely issued[ citation needed]||Vehicle carry only|
|South Carolina||Partial (25 states);
Resident permits only
|Texas|| ||Partial (43 states)|
|United States Virgin Islands||In practice[ citation needed]||Has reciprocity law, but does not recognize any other state permits|
|Washington||Partial (10 states)|
|West Virginia||   ||For reciprocity purposes.||Partial (35 states)|
|Wisconsin||Partial (42 states)|
|Wyoming||Wyoming residents only.||For reciprocity purposes.||Partial (35 states)|
|U.S. Military installations||||No|
|Native American reservations||Varies||Varies|
State regulations relating to the issuance of concealed carry permits generally fall into four categories described as Unrestricted, Shall Issue, May Issue, and No Issue.
An unrestricted jurisdiction is one in which a permit is not required to carry a concealed handgun. This is sometimes called constitutional carry. Within the unrestricted category, there exists states that are fully unrestricted, where no permit is required for lawful open or concealed carry, and partially unrestricted, where certain forms of concealed carry may be legal without a permit, while other forms of carry may require a permit.
Among U.S. states, Alaska, Arizona, Arkansas, Idaho (residents only), Kansas, Maine, Mississippi, Missouri, New Hampshire, North Dakota (residents only; concealed carry only), Vermont, West Virginia  and Wyoming (residents only) are fully unrestricted, and allow those who are not prohibited from owning a firearm to carry a concealed firearm in any place not deemed off-limits by law without a permit. Idaho, North Dakota and Wyoming only extend permitless carry to residents of the state; non-residents must still have a permit issued by their home state to legally carry concealed in these states. Permitless concealed carry in Mississippi only covers certain manners of carrying; see table above. These states also allow the open carry of a handgun without a permit with the exception of North Dakota and certain localities in Missouri.     
Vermont does not have any provision for issue of concealed-carry licenses, as none has ever been necessary. As such, Vermont residents wishing to carry handguns in other states must acquire a license from a state which is valid in their destination. A popular choice is Florida's concealed handgun permit, which is valid for nonresident holders in 28 other states. All other constitutional carry states previously had concealed-carry license requirements prior to adoption of unrestricted carry laws, and continue to issue licenses on a shall-issue basis for the purposes of inter-state reciprocity (allowing residents of the state to travel to other states with a concealed weapon, abiding by that state's law).
The states of Montana, New Mexico, and Oklahoma are partially unrestricted states. Specifically, Montana currently allows concealed carry without a permit in places outside of any incorporated municipality. New Mexico laws allow an individual to conceal carry an unloaded handgun without a permit. New Mexico further allows one to carry a loaded handgun either openly or concealed while traveling in a vehicle, including motorcycles, recreational vehicles (RVs), bicycles or while riding a horse. Oklahoma allows residents of permitless carry states to carry openly or concealed without a permit, provided such individuals have a valid ID from their home state. All of the aforementioned states grant permits on a shall-issue basis for modes of concealed carry that require a permit.
On July 24, 2014, Washington D.C. became a constitutional carry jurisdiction for a brief moment when its ban on carrying a handgun was ruled unconstitutional and the ruling was not stayed.  The ruling said that any resident who had a legally registered handgun could carry it without a permit and non-residents without felony convictions could carry as well. The ruling was then stayed on July 29, 2014.    
A shall-issue jurisdiction is one that requires a license to carry a concealed handgun, but where the granting of such licenses is subject only to meeting determinate criteria laid out in the law; the granting authority has no discretion in the awarding of the licenses, and there is no requirement of the applicant to demonstrate "good cause". The laws in a Shall-Issue jurisdiction typically state that a granting authority shall issue a license if the criteria are met, as opposed to laws in which the authority may issue a license at their discretion.
Typical license requirements include residency, minimum age, submitting fingerprints, passing a computerized instant background check (or a more comprehensive manual background check), attending a certified handgun/firearm safety class, passing a practical qualification demonstrating handgun proficiency, and paying a required fee. These requirements vary widely by jurisdiction, with some having few or none of these and others having most or all.
The following are shall-issue states: Alabama, Alaska, Arizona, Arkansas, Colorado, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, North Carolina,  North Dakota, Ohio, Oklahoma, Oregon,  Pennsylvania, Rhode Island (for permits issued by local authorities), South Carolina, South Dakota, Tennessee,  Texas,   Utah,  Virginia, Washington, West Virginia, Wisconsin, and Wyoming.  The territory of Guam is also Shall-Issue with the passage of Bill 296. 
Certain states and jurisdictions, while "may-issue" by law, direct their issuing authorities to issue licenses to all or nearly all qualified applicants, and as such they are considered "shall-issue" in practice. Connecticut, and certain cities and counties in California, Massachusetts, and New York are examples.[ citation needed]
Connecticut law specifies that CCW licenses be granted on a may-issue basis, but the state's courts have established that issuing authorities must grant CCW licenses on a shall-issue basis for applicants who meet all statutory qualifications, as unlike other may-issue states Connecticut law does not contain a requirement for the applicant to show "necessary and proper reason" for obtaining a license.[ citation needed]
States with pure shall-issue licensing laws require the issuing authority to issue permits to any applicant who has submitted a properly-completed application, passed a background check, completed any required training, and met any other criteria specified by law. The issuing authority has no discretion to deny permits based on factors beyond the qualification criteria specified by law.[ citation needed]
Shall-issue with limited discretion is a subset of shall-issue licensing that borders between pure shall-issue and may-issue policy, where an issuing authority has a limited degree of discretion to deny applicants a concealed carry permit based either on the applicant's suitability or reason for requesting a permit, even after the applicant has completed any required training and passed a background check. In states with such licensing practices, the issuing authority would be required to demonstrate with substantiating evidence, that the applicant is either not suitable or lacks appropriate need for the permit. Most denials in such states are typically reversed upon appeal provided the applicant has passed a background check and fulfilled any training requirements for the permit. States with shall-issue laws that allow a limited degree of discretion include Illinois, Indiana, Minnesota, New Hampshire, Oregon, and Pennsylvania. Although may-issue by statute, Connecticut also falls into this subset, in practice.
Some shall-issue jurisdictions allow for automatic renewal of concealed carry permits, as long as the permit-holder files the renewal application before the permit expires (or in some states, a short grace period following expiration of the original permit). Other jurisdictions require a permit-holder to complete refresher training in firearms safety and undergo a criminal background check before applying for renewal. Some jurisdictions periodically run permit holders' IDs through the NICS background check system. Other jurisdictions require a judge to suspend a permit if the holder is arrested for certain offenses (return/revocation of the permit depending on later disposition of the case).
A may-issue jurisdiction is one that requires a permit to carry a concealed handgun, and where the granting of such permits is partially at the discretion of local authorities (frequently the sheriff's department or police), with a few states consolidating this discretionary power under state-level law enforcement. Moreover, issuing authorities in most may-issue jurisdictions are not required to provide a substantive reason for the denial of a concealed carry permit. Some may-issue jurisdictions may provide administrative and legal avenues for an applicant to appeal a permit denial, while others do not.
The law typically states that a granting authority "may issue" a permit if various criteria are met, or that the permit applicant must have "good cause" (or similar) to carry a concealed weapon. In most such situations, self-defense in and of itself often does not satisfy the "good cause" requirement, and issuing authorities in some may-issue jurisdictions have been known to arbitrarily deny applications for CCW permits without providing the applicant with any substantive reason for the denial. Some may-issue jurisdictions require a permit-holder to provide justification for continued need for a concealed carry permit upon renewal, and may deny the renewal of an expiring permit without sufficient showing of "good cause." Some of these jurisdictions may revoke a permit after it has been issued when the issuing authority in its discretion has determined that the "good cause" used in approving the permit application no longer exists. Other may-issue jurisdictions allow for automatic renewal of the permit, as long as the permit-holder completes any required firearms safety training and files the renewal application before the permit expires. Some may-issue jurisdictions give issuing authorities discretion in granting concealed carry permits based on an applicant's suitability (e.g., moral character) by requiring the applicant to submit evidence (resume/curriculum vitae, letters of reference, credit history, etc.) showing the applicant is of suitable character to be issued a permit.
When distinguishing between shall-issue and may-issue, that distinction may not necessarily be explicitly apparent in the exact letter of the law. Rather, a more accurate determinant as to whether a state is shall-issue versus may-issue is whether or not the applicant is required to show "good cause" when applying for a permit. Court precedent also plays an important role in determining whether a state is may-issue or shall-issue without regard to the verbiage in state law. For example, New York is a may-issue state, even though its concealed carry licensing laws includes the words "shall issue," because New York law requires applicants to show "good cause" when applying for a concealed carry permit. Since "good cause" is highly subjective, issuing authorities in New York have wide discretion in determining what constitutes "good cause," and the ability for an ordinary citizen to obtain a concealed carry permit varies widely throughout the state. In contrast, the pistol permit law in neighboring Connecticut contains the words "may issue," despite Connecticut effectively being a shall-issue state. This is because Connecticut's pistol permit law does not require the applicant to show "good cause" to the issuing authority when applying for a pistol permit. Because Connecticut's permitting law lacks a subjective "good cause" standard, that state's courts have repeatedly and consistently ruled that issuing authorities must issue pistol permits to applicants who meet the state's statutory qualifications for a pistol permit.
May-issue can be compared to shall-issue where in a may-issue jurisdiction, the burden of proof for justifying the need for a permit rests with the applicant, whereas in a shall-issue jurisdiction the burden of proof to justify denying a permit rests with the issuing authority.
A state that is de jure a may-issue jurisdiction may range anywhere from shall-issue to no-issue in practice,   i.e., permissive may-issue to restrictive may-issue, based on each licensing authority's willingness to issue permits to applicants:
- Connecticut and Delaware are regarded as permissive may-issue states, where either governmental policy or court precedence direct issuing authorities to approve applications that meet all non-discretionary criteria.
- Hawaii, Maryland, and New Jersey are considered restrictive may-issue jurisdictions, where issuing authorities are directed to deny most or all applications, either based on hard-to-meet "good cause" requirements or agency policies specifically prohibiting issue. Additionally Maryland and New Jersey require the applicant provide substantive evidence of a clear and immediate threat on their lives that exists outside of their home at the time the permit application is filed. Rhode Island further requires applicants for the statewide permit to submit to a mental health records check at the applicant's expense.
- California, Massachusetts, and New York vary within state, as the criteria for what constitutes "good cause" is defined at the local level. Issuing authorities in inland California, rural portions of Massachusetts, and Upstate New York generally accept self-defense without evidence of a specific threat as "good cause" and will grant permits to the vast majority of applicants who pass a background check and complete the required firearms safety training. Meanwhile, concealed carry permits are difficult to virtually impossible to obtain by ordinary citizens in urban areas, such as New York City, Long Island, Boston, Los Angeles, and San Francisco metropolitan areas. In these locations, the definition of "good cause" is generally limited to specific and immediate threats on an applicant's life that cannot be mitigated by any other means. There are also "moderately restrictive" local jurisdictions in these states where the local "good cause" definitions may be more restrictive than locales that practice shall-issue licensing, but less restrictive than those counties or municipalities that rarely or never issue permits.
- Rhode Island state law is two-tier; local authorities are directed by state law and court precedent (Archer v McGarry) to practice shall-issue permitting policy, but the Attorney General's office has discretionary authority over permits issued by its office. The permits issued by both the local authorities and the AG are valid statewide, but the AG issued permit is required for open carry in general. Some local jurisdictions, at the recommendation of the AG, still refer all applicants to the AG's office and the "may-issue" state-level system in violation of Archer. 
In some may-issue jurisdictions, permits are only issued to individuals with celebrity status, have political connections, or have a high degree of wealth,    resulting in accusations of systematic corruption in how CCW permit applications are adjudicated in some such jurisdictions.  Additionally, issuing authorities charge arbitrarily defined fees that go well beyond the basic processing fee for a CCW permit, thereby making the CCW permit unaffordable to most applicants. For example, applying for a New York City concealed carry permit typically costs around $5,000 when the filing fee and other administrative fees are combined.
In recent cases challenging restrictive discretionary issue laws, federal district and appeals courts have generally applied intermediate scrutiny to these and other Second Amendment related cases, where the courts recognize that restrictive concealed carry laws "infringe on an individual's right to keep and bear arms," but also recognizes that such infringement is permitted to further "an important government interest in public safety." Any and all other Rights that are described as "individual" and "fundamental" by the SCOTUS require a "strict scrutiny" standard as shown in prior decisions involving fully applicable incorporation cases. In Maryland, Woollard v. Sheridan, the United States District Court for the District of Maryland decided in favor of a Maryland resident who was denied a permit renewal due to lack of "good cause" in accordance with Maryland law.  The United States Court of Appeals for the Fourth Circuit reversed, holding the "good cause" requirement met the standard of intermediate scrutiny applicable to restrictions on the right to carry arms outside the home, and reinstated the "good cause" requirement on March 21, 2013.  The plaintiffs in the case filed a petition for certiorari in the United States Supreme Court; the court denied certiorari without comment on October 15.  New York's similar "good cause" requirement was also under challenge in Kachalsky v. Cacase. However, certiorari before SCOTUS was denied on April 15, 2013. Drake v. Filko, involving several plaintiffs (including one kidnap victim) denied permits under New Jersey's permitting system; the suit challenged New Jersey's "justifiable need" requirement for obtaining a carry permit. The United States Court of Appeals for the Third Circuit affirmed the lower court's judgment holding the requirement constitutional, holding (much like the 4th Circuit in Woollard and the 2nd Circuit in Kachalsky) that the New Jersey statute survived intermediate scrutiny.  The common theme from Courts of Appeals rulings upholding may-issue laws is that state or local policies in limiting who is granted permits to carry firearms in public "furthers an important government interest in public safety," by which state legislatures enact laws making licensed concealed carry available but establish criteria to limit the number of concealed carry permit-holders to as few as practicable to pass constitutional muster. The courts have opined that these laws survive intermediate scrutiny on that basis. However, all other "fundamental" and "individual" Rights are subjected to a "strict scrutiny" standard, see, Duncan, 391 U.S. at 149, and n. 15, supra., "A right that is fundamental from an American perspective applies equally to the Federal Government and the States."
While members of the Armed Services may receive extensive small arms training, United States Military installations have some of the most restrictive rules for the possession, transport, and carrying of personally-owned firearms in the country.
Overall authority for carrying a personally-owned firearm on a military installation rests with the installation commander, although the authority to permit individuals to carry firearms on an installation is usually delegated to the Provost Marshal. Military installations do not recognize state-issued concealed carry permits, and state firearms laws generally do not apply to military bases, regardless of the state in which the installation is located. Federal law (18 USC, Section 930) generally forbids the possession, transport, and carrying of firearms on military installations without approval from the installation commander. Federal law gives installation commanders wide discretion in establishing firearms policies for their respective installations. In practice, local discretion is often constrained by policies and directives from the headquarters of each military branch and major commands.
Installation policies can vary from no-issue for most bases to shall-issue in rare circumstances. Installations that do allow the carrying of firearms typically restrict carrying to designated areas and for specific purposes (i.e., hunting or officially sanctioned shooting competitions in approved locations on the installation). Installation commanders may require the applicant complete extensive firearms safety training, undergo a mental health evaluation, and obtain a letter of recommendation from his or her unit commander (or employer) before such authorization is granted. Personnel that reside on a military installation are typically required to store their personally-owned firearms in the installation armory, although the installation commander or provost marshal may permit a servicemember to store his or her personal firearms in their on-base dwelling if he or she has a gun safe or similarly designed cabinet where the firearms can be secured.
Prior to 2011, military commanders could impose firearms restrictions to servicemembers residing off-base, such as mandatory registration of firearms with the base Provost Marshal, restricting or banning the carrying of firearms by servicemembers either on or off the installation regardless of whether the member had a state permit to carry, and requiring servicemembers to have a gun safe or similar container to secure firearms when not in use. A provision was included in the National Defense Authorization Act for Fiscal Year 2011 that limited commanders' authority to impose restrictions on the possession and use of personally-owned firearms by servicemembers who reside off-base.
A no-issue jurisdiction is one that – with very limited exceptions – does not allow any private citizen to carry a concealed handgun in public. The term refers to the fact that no concealed carry permits will be issued (or recognized). Since July 2013, with the legalization of concealed carry in Illinois, there are presently no no-issue per se; with only the territory of American Samoa being the only U.S. jurisdiction that completely prohibits concealed carry.
While technically may-issue under state law, Hawaii, Maryland, New Jersey, and certain cities and counties within California, Massachusetts, and New York are no-issue jurisdictions in practice, with governmental policy directing officials with discretionary power to rarely or never issue licenses. Additionally, some of the United States' insular territories ( U.S. Virgin Islands, American Samoa, etc.) are no-issue jurisdictions in practice. Most no-issue jurisdictions have exceptions to their laws that permit open or concealed carry by active and retired law enforcement officials, armed security personnel while on duty and in uniform, and for members of the Armed Forces. Wisconsin and Illinois were the last remaining no-issue states, until licensed concealed carry was legalized in 2011 and 2013, respectively. Prior to legalization, Wisconsin outlawed concealed carry, but open carry was legal statewide. Illinois had banned concealed carry, and generally prohibited open carry in most locations as well.
Prohibitions of the concealed carry of firearms and other weapons by local governments predate the establishment of the United States. In 1686, New Jersey law stated “no person or persons … shall presume privately to wear any pocket pistol … or other unusual or unlawful weapons within this Province.” After the federal government was established, states and localities continued to restrict people from carrying hidden weapons. Tennessee law prohibited this as early as 1821. By 1837, Georgia passed into effect “An Act to guard and protect the citizens of this State, against the unwarrantable and too prevalent use of deadly weapons.” Two years later, Alabama followed suit with “An Act to Suppress the Evil Practice of Carrying Weapons Secretly.” Delaware prohibited the practice in 1852.  Ohio did the same in 1859, a policy that remained in effect until 1974.  Cities also regulated weapons within their boundaries. In 1881, Tombstone, Arizona enacted Ordinance No. 9 "To Provide against Carrying of Deadly Weapons," a regulation that sparked the Gunfight at the O.K. Corral later that year.
Most may-issue jurisdictions, and some shall-issue jurisdictions allow issuing authorities to impose limitations on CCW permits, such as the type and caliber of handguns that may be carried ( Massachusetts, New Mexico), restrictions on places where the permit is valid ( New York, Rhode Island, Illinois), restricting concealed carry to purposes or activities specified on the approved permit application ( California, Massachusetts, New Jersey, New York), limitations on magazine size ( Connecticut, Massachusetts, New York), or limitations on the number of firearms that may be carried concealed by a permit-holder at any given time (some states). Permits issued by all but two states (New York and Hawaii) are valid statewide. New York State pistol licenses, which are generally issued by counties, are valid statewide with one exception. A permit not issued by New York City is invalid in that city, unless validated by its police commissioner.   Permits issued by Hawaii are valid only in the county of issuance.
Some states require concealed carry applicants to certify their proficiency with a firearm through some type of training or instruction. Certain training courses developed by the National Rifle Association that combine classroom and live-fire instruction typically meet most state training requirements. Some states recognize prior military or police service as meeting training requirements. 
Classroom instruction would typically include firearm mechanics and terminology, cleaning and maintenance of a firearm, concealed carry legislation and limitations, liability issues, carry methods and safety, home defense, methods for managing and defusing confrontational situations, and practice of gun handling techniques without firing the weapon. Most required CCW training courses devote a considerable amount of time to liability issues.
Depending on the state, a practical component during which the attendee shoots the weapon for the purpose of demonstrating safety and proficiency, may be required. During range instruction, applicants would typically learn and demonstrate safe handling and operation of a firearm and accurate shooting from common self-defense distances. Some states require a certain proficiency to receive a passing grade, whereas other states (e.g., Florida) technically require only a single-shot be fired to demonstrate handgun handling proficiency.
CCW training courses are typically completed in a single day and are good for a set period, the exact duration varying by state. Some states require re-training, sometimes in a shorter, simpler format, for each renewal.
A few states, e.g., South Carolina, recognize the safety and use-of-force training given to military personnel as acceptable in lieu of formal civilian training certification. Such states will ask for a military ID (South Carolina) for active persons or DD214 for honorably discharged persons. These few states will commonly request a copy of the applicant's BTR (Basic Training Record) proving an up-to-date pistol qualification. Active and retired law enforcement officers are generally exempt from qualification requirements, due to a federal statute permitting retired law enforcement officers to carry concealed weapons in the United States. 
Virginia recognizes eight specific training options to prove competency in handgun handling, ranging from DD214 for honorably discharged military veterans, to certification from law enforcement training, to firearms training conducted by a state or NRA certified firearms instructor including electronic, video, or on-line courses. While any one of the eight listed options will be considered adequate proof, individual circuit courts may recognize other training options.  A small number of states, such as Alabama and Georgia, have no training requirements to obtain a permit—only a requirement that the applicant successfully pass the required background check before issuance.
Many jurisdictions recognize (honor) a permit or license issued by other jurisdictions. Recognition may be granted to all jurisdictions or some subset which meets a set of permit-issuing criteria, such as training comparable to the honoring jurisdiction or certain background checks. Several states have entered into formal agreements to mutually recognize permits. This arrangement is commonly called reciprocity or mutual recognition. A few states do not recognize permits issued by any other jurisdiction, but offer non-resident permits for out-of-state individuals (who possess a valid concealed carry permit from their home state) who wish to carry while visiting such states. There are also states that neither recognize out-of-state concealed carry permits nor issue permits to non-residents, resulting in a complete ban on concealed carry by non-residents in such states.
Recognition and reciprocity of concealed carry privileges varies. Some states (e.g. Indiana, Kentucky, Ohio) unilaterally recognize all permits. Others such as Michigan, limit such universal recognition to residents of the permit-issuing state.  While 37 states have reciprocity agreements with at least one other state and several states honor all out-of-state concealed carry permits, some states have special requirements like training courses or safety exams, and therefore do not honor permits from states that do not have such requirements for issue. Some states make exceptions for persons under the minimum age (usually 21) if they are active or honorably-discharged members of the military or a police force (the second of these two is allowed under Federal law). States that do not have this exemption generally do not recognize any license from states that do. An example of this is the State of Washington's refusal to honor any Texas LTC as Texas has the military exception to age.  Idaho and Missouri also have standard and enhanced permits that have different requirements to obtain and also have unique reciprocity with different states. 
Ohio permits have the highest recognition in 40 states. One can obtain multiple state permits in an effort to increase the number of states where that user can carry a legally concealed weapon. It is common practice to use a CCW Reciprocity Map  to gain clarity on which states will honor the person's combination of resident and non-resident permits given the variety of standards and legal policies from state to state. There are also various mobile applications  that guide users in researching state concealed carry permit reciprocity.
Although carry may be legal under State law in accordance with reciprocity agreements, the Federal Gun Free School Zones Act subjects an out-of-state permit holder to federal felony prosecution if they carry a firearm within 1000 feet of any K–12 school's property line; however, the enforcement of this statute is rare given several states' nullification statutes prohibiting state law enforcement officers from enforcing federal firearms laws.
While generally a concealed carry permit allows the permit holder to carry a concealed weapon in public, a state may restrict carry of a firearm including a permitted concealed weapon while in or on certain properties, facilities or types of businesses that are otherwise open to the public. These areas vary by state (except for the first item below; Federal offices are subject to superseding Federal law) and can include:
- Federal government facilities, including post offices, IRS offices, federal court buildings, military/VA facilities and/or correctional facilities, Amtrak trains and facilities, and Corps of Engineers-controlled property (carry in these places is prohibited by Federal law and preempts any existing State law). Carry on land controlled by the Bureau of Land Management (federal parks and wildlife preserves) is allowed by Federal law as of the 2009 CARD Act, but is still subject to state law. However, carry into restrooms or any other buildings or structures located within federal parks is illegal in the United States, despite concealed carry being otherwise legal in federal parks with a permit recognized by the state in which the federal park is located. Similarly, concealed carry into caves located within federal parks is illegal.
- State and local government facilities, including courthouses, DMV/DoT offices, police stations, correctional facilities, and/or meeting places of government entities (exceptions may be made for certain persons working in these facilities such as judges, lawyers, and certain government officials both elected and appointed)
- Venues for political events, including rallies, parades, debates, and/or polling places
- Educational institutions including elementary/secondary schools and colleges. Some states have "drop-off exceptions" which only prohibit carry inside school buildings, or permit carry while inside a personal vehicle on school property. Campus carry laws vary by state.
- Public interscholastic[ citation needed] and/or professional sporting events and/or venues (sometimes only during a time window surrounding such an event)
- Amusement parks, fairs, parades and/or carnivals[ citation needed]
- Businesses that sell alcohol (sometimes only "by-the-drink" sellers like restaurants, sometimes only establishments defined as a "bar" or "nightclub", or establishments where the percentage of total sales from alcoholic beverages exceeds a specified threshold)
- Hospitals (even if hospitals themselves are not restricted, "teaching hospitals" partnered with a medical school are sometimes considered "educational institutions"; exceptions are sometimes made for medical professionals working in these facilities)
- Churches, mosques and other "Houses of worship," usually at the discretion of the church clergy (Ohio allows with specific permission of house of worship) 
- Municipal mass transit vehicles or facilities
- Sterile areas of airports (sections of the airport located beyond security screening checkpoints, unless explicitly authorized)
- Non-government facilities with heightened security measures (Nuclear facilities, power plants, dams, oil and gas production facilities, banks, factories, unless explicitly authorized)
- Aboard aircraft or ships unless specifically authorized by the pilot in command or ship captain
- Private property where the lawful owner or lessee has posted a sign or verbally stated that firearms are not permitted
- Any public place, while under the influence of alcohol or drugs (including certain prescription or over-the-counter medications, depending on jurisdiction)
Some states allow private businesses to post a specific sign prohibiting concealed carry within their premises. The exact language and format of such a sign varies by state. By posting the signs, businesses create areas where it is illegal to carry a concealed handgun; similar to regulations concerning schools, hospitals, and public gatherings.
Violation of such a sign, in some of these states, is grounds for revocation of the offender's concealed carry permit and criminal prosecution. Other states, such as Virginia, enforce only trespassing laws when a person violates a "Gun Free Zone" sign. In some jurisdictions trespass by a person carrying a firearm may have more severe penalties than "simple" trespass, while in other jurisdictions, penalties are lower than for trespass. 
Such states include: Arizona, Arkansas, Connecticut, Illinois, Kansas, Louisiana, Michigan, Minnesota, Missouri, Nebraska,  Nevada, New Mexico, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and Wisconsin.
There is considerable dispute over the effectiveness of such " gun-free zones". Opponents of such measures, such as OpenCarry.org, state that, much like other malum prohibitum laws banning gun-related practices, only law-abiding individuals will heed the signage and disarm. Individuals or groups intent on committing far more serious crimes, such as armed robbery or murder, will not be deterred by signage prohibiting weapons. Further, the reasoning follows that those wishing to commit mass murder might intentionally choose gun-free venues like shopping malls, schools and churches (where weapons carry is generally prohibited by statute or signage) because the population inside is disarmed and thus less able to stop them.  
In some states, business owners have been documented posting signs that appear to prohibit guns, but legally do not because the signs do not meet local or state laws defining required appearance, placement, or wording of signage. Such signage can be posted out of ignorance to the law, or intent to pacify gun control advocates while not actually prohibiting the practice. The force of law behind a non-compliant sign varies based on state statutes and case law. Some states interpret their statutes' high level of specification of signage as evidence that the signage must meet the specification exactly, and any quantifiable deviation from the statute makes the sign non-binding. Other states have decided in case law that if efforts were made in good faith to conform to the statutes, the sign carries the force of law even if it fails to meet current specification. Still others have such lax descriptions of what is a valid sign that virtually any sign that can be interpreted as "no guns allowed" is binding on the license holder.[ citation needed]
Note that virtually all jurisdictions allow some form of oral communication by the lawful owner or controller of the property that a person is not welcome and should leave. This notice can be given to anyone for any reason (except for statuses that are protected by the Federal Civil Rights Act of 1964 and other CRAs, such as race),[ citation needed] including due to the carrying of firearms by that person, and refusal to heed such a request to leave may constitute trespassing.
Printing refers to a circumstance where the shape or outline of a firearm is visible through a garment while the gun is still fully covered, and is generally not desired when carrying a concealed weapon. Brandishing can refer to different actions depending on jurisdiction. These actions can include printing through a garment, pulling back clothing to expose a gun, or unholstering a gun and exhibiting it in the hand. The intent to intimidate or threaten someone may or may not be required legally for it to be considered brandishing.
Brandishing is a crime in most jurisdictions, but the definition of brandishing varies widely.
Under California law, the following conditions have to be present to prove brandishing:
 A person, in the presence of another person, drew or exhibited a [deadly weapon, other than a firearm] [firearm, whether loaded or unloaded]; [and]  That person did so in a rude, angry, or threatening manner [or]  That person, in any manner, unlawfully used the [deadly weapon] [firearm] in a fight or quarrel] [.] [; and  The person was not acting in lawful self-defense.] 
In Virginia law:
It shall be unlawful for any person to point, hold or brandish any firearm or any air or gas operated weapon or any object similar in appearance, whether capable of being fired or not, in such manner as to reasonably induce fear in the mind of another or hold a firearm or any air or gas operated weapon in a public place in such a manner as to reasonably induce fear in the mind of another of being shot or injured. However, this section shall not apply to any person engaged in excusable or justifiable self-defense.— Code of Virginia 18.2-282 
The Gun Control Act passed by Congress in 1968 lists felons, illegal aliens, and other codified persons as prohibited from purchasing or possessing firearms. During the application process for concealed carry states carry out thorough background checks to prevent these individuals from obtaining permits. Additionally the Brady Handgun Violence Prevention Act created an FBI maintained system in 1994 for instantly checking the backgrounds of potential firearms buyers in an effort to prevent these individuals from obtaining weapons.
The Firearm Owners Protection Act (FOPA) of 1986 allows a gun owner to travel through states in which their firearm possession is illegal as long as it is legal in the states of origination and destination, the owner is in transit and does not remain in the state in which firearm possession is illegal, and the firearm is transported unloaded and in a locked container. The FOPA addresses the issue of transport of private firearms from origin to destination for purposes lawful in state of origin and destination; FOPA does not authorize concealed carry as a weapon of defense during transit. New York State Police arrested those carrying firearms in violation of state law, and then required them to use FOPA as an affirmative defense to the charges of illegal possession.[ citation needed]
In 2004, the United States Congress enacted the Law Enforcement Officers Safety Act, 18 U.S. Code 926B and 926C. This federal law allows two classes of persons – the "qualified law enforcement officer" and the "qualified retired law enforcement officer" – to carry a concealed firearm in any jurisdiction in the United States, regardless of any state or local law to the contrary, with certain exceptions.
The Federal Gun Free School Zone Act limits where a person may legally carry a firearm. It does this by making it generally unlawful for an armed citizen to be within 1,000 feet (extending out from the property lines) of a place that the individual knows, or has reasonable cause to believe, is a K–12 school. Although a state-issued carry permit may exempt a person from this restriction in the state that physically issued their permit, it does not exempt them in other states which recognize their permit under reciprocity agreements made with the issuing state.
The law's failure to provide adequate protection to LEOSA-qualified officers, licensed concealed carry permit holders, and other armed citizens, is an issue that the United States Congress so far has not addressed.[ citation needed]
On May 22, 2009, President Barack Obama signed H.R. 627, the "Credit Card Accountability Responsibility and Disclosure Act of 2009," into law. The bill contained a rider introduced by Senator Tom Coburn (R-OK) that prohibits the Secretary of the Interior from enacting or enforcing any regulations that restrict possession of firearms in National Parks or Wildlife Refuges, as long as the person complies with laws of the state in which the unit is found.  This provision was supported by the National Rifle Association and opposed by the Brady Campaign to Prevent Gun Violence, the National Parks Conservation Association, and the Coalition of National Park Service Retirees, among other organizations.   As of February 2010 concealed handguns are for the first time legal in all but 3 of the nation's 391 national parks and wildlife refuges so long as all applicable federal, state, and local regulations are adhered to.  Hawaii is a notable exception. Concealed and open carry are both illegal in Hawaii for all except retired military or law enforcement personnel. Previously firearms were allowed into parks if cased and unloaded.
Attempts were made in the 110th Congress, United States House of Representatives (H.R. 226) and the United States Senate (S. 388), to enact legislation to compel complete reciprocity for concealed carry licenses. Opponents of national reciprocity have pointed out that this legislation would effectively require states with more restrictive standards of permit issuance (e.g., training courses, safety exams, "good cause" requirements, et al.) to honor permits from states with more liberal issuance policies. Supporters have pointed out that the same situation already occurs with marriage certificates, adoption decrees and other state documents under the "full faith and credit" clause of the U.S. Constitution.  Some states have already adopted a "full faith and credit" policy treating out-of-state carry permits the same as out-of-state driver's license or marriage certificates without federal legislation mandating such a policy.  In the 115th Congress, another universal reciprocity bill, the Concealed Carry Reciprocity Act of 2017, was introduced by Richard Hudson. The bill passed the House and is awaiting a vote by the Senate. 
Prior to the 1897 Supreme Court case Robertson v. Baldwin,  the federal courts had been silent on the issue of concealed carry. In the dicta from a maritime law case the Supreme Court commented that state laws restricting concealed weapons do not infringe upon the right to bear arms protected by the Federal Second Amendment. 
Like most rights, the Second Amendment right is not unlimited. It is not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose: For example, concealed weapons prohibitions have been upheld under the Amendment or state analogues ... The majority of the 19th-century courts to consider the question held that prohibitions on carrying concealed weapons were lawful under the Second Amendment or state analogues. 
Heller was a landmark case because for the first time in United States history a Supreme Court decision defined the right to bear arms as constitutionally guaranteed to private citizens rather than a right restricted to "well regulated militia[s]". The Justices asserted that sensible restrictions on the right to bear arms are constitutional, however, an outright ban on a specific type of firearm, in this case handguns, was in fact unconstitutional. The Heller decision is limited because it only applies to federal enclaves such as the District of Columbia. In 2010 the SCOTUS expanded Heller in McDonald v. Chicago incorporating the 2nd Amendment through the 14th Amendment as applying to local and state laws. Various Circuit Courts have upheld their local and state laws using intermediate scrutiny. The correct standard is strict scrutiny review for all "fundamental" and "individual" rights.   On June 28, 2010, the U.S. Supreme Court struck down the handgun ban enacted by the city of Chicago, Illinois, in McDonald v. Chicago, effectively extending the Heller decision to states and local governments nationwide.  Banning handguns in any jurisdiction has the effect of rendering invalid any licensed individual's right to carry concealed in that area except for federally exempted retired and current law enforcement officers and other government employees acting in the discharge of their official duties.
Even when self-defense is justified, there can be serious civil or criminal liabilities related to self-defense when a concealed carry permit holder brandishes or fires his/her weapon. For example, if innocent bystanders are hurt or killed, there could be both civil and criminal liabilities even if the use of deadly force was completely justified.   Some states technically allow an assailant who is shot by a gun owner to bring civil action. In some states, liability is present when a resident brandishes the weapon, threatens use, or exacerbates a volatile situation, or when the resident is carrying while intoxicated. It is important to note that simply pointing a firearm at any person constitutes felony assault with a deadly weapon unless circumstances validate a demonstration of force. A majority of states who allow concealed carry, however, forbid suits being brought in such cases, either by barring lawsuits for damages resulting from a criminal act on the part of the plaintiff, or by granting the gun owner immunity from such a civil suit if it is found that he or she was justified in shooting.
Simultaneously, increased passage of " Castle Doctrine" laws allow persons who own firearms and/or carry them concealed to use them without first attempting to retreat. The " Castle Doctrine" typically applies to situations within the confines of one's own home.  Nevertheless, many states have adopted escalation of force laws along with provisions for concealed carry. These include the necessity to first verbally warn a trespasser or lay hands on a trespasser before a shooting is justified (unless the trespasser is armed or assumed to be so). This escalation of force does not apply if the shooter reasonably believes a violent felony has been or is about to be committed on the property by the trespasser. Additionally some states have a duty to retreat provision which requires a permit holder, especially in public places, to vacate him or herself from a potentially dangerous situation before resorting to deadly force. The duty to retreat does not restrictively apply in a person's home or business though escalation of force may be required. In 1895 the Supreme Court ruled in Beard v. United States (1895) that if an individual does not provoke an assault and is residing in a place they have a right to be then they may use considerable force against someone they reasonably believe may do them serious harm without being charged with murder or manslaughter should that person be killed.  Further, in Texas  and California   homicide is justifiable solely in defense of property. In other states, lethal force is only authorized when serious harm is presumed to be imminent.
Even given these relaxed restrictions on use of force, using a handgun must still be a last resort in some jurisdictions; meaning the user must reasonably believe that nothing short of deadly force will protect the life or property at stake in a situation. Additionally, civil liabilities for errors that cause harm to others still exist, although civil immunity is provided in the Castle Doctrine laws of some states (e.g., Texas). 
Criminal possession of a weapon is the unlawful possession of a weapon by a citizen. Many societies both past and present have placed restrictions on what forms of weaponry private citizens (and to a lesser extent police) are allowed to purchase, own, and carry in public. Such crimes are public order crimes and are considered mala prohibita, in that the possession of a weapon in and of itself is not evil. Rather, the potential for use in acts of unlawful violence creates a possible need to control them. Some restrictions are strict liability, whereas others require some element of intent to use the weapon for an illegal purpose. Some regulations allow a citizen to obtain a permit or other authorization to possess the weapon under certain circumstances. Lawful uses of weapons by civilians commonly include hunting, sport, collection and self-preservation.
The penalties for carrying a firearm in an unlawful manner varies widely from state-to-state, and may range from a simple infraction punishable by a fine to a felony conviction and mandatory incarceration. An individual may also be charged and convicted of criminal charges other than unlawful possession of a firearm, such as assault, disorderly conduct, or disturbing the peace. In the case of an individual with no prior criminal convictions, the state of Tennessee classifies the unlawful concealed carry of a loaded handgun as a Class C misdemeanor punishable by a maximum of 30 days imprisonment and/or a $500 fine.  While in New York State, a similar crime committed by an individual with no criminal convictions is classified as a Class D felony, punishable by a mandatory minimum of 3.5 years imprisonment, to a maximum of 7 years.   As New York State does not recognize any pistol permits issued in other states, the statute would apply to any individual who does not have a valid New York State issued concealed carry permit, even if such individual has a valid permit issued in another jurisdiction.  In addition, the New York State statutory definition of a "loaded firearm" differs significantly from what may be commonly understood, as simply possessing any ammunition along with a weapon capable of firing such ammunition satisfies the legal definition of a loaded firearm in New York.  The large variability of state carry laws has resulted in confusing circumstances where a person in Vermont (which requires no license of any kind to carry a concealed weapon by anyone who is not prohibited by law), could unwittingly travel into the adjacent state of New York, where such individual, despite acting entirely within the law of Vermont, would then face a mandatory 3.5 year prison sentence simply for accidentally crossing the state's border into New York. These circumstances are aggravated by the fact that many NYS police departments as well as the New York State Police do not recognize the protections granted federally under the Firearm Owners Protection Act, which was intended to prevent such prosecutions. 
A comprehensive 2004 review of the existing literature by the National Academy of Sciences found that the results of existing studies were sensitive to the specification and time period examined, and concluded that a causal link between right-to-carry laws and crime rates cannot be shown.  Quinnipiac University economist Mark Gius summarized literature published between 1993 and 2005, and found that ten papers suggested that permissive CCW laws reduce crime, one paper suggested they increase crime, and nine papers showed no definitive results.  A 2016 study in the European Economic Review which examined the conflicting claims in the existing literature concluded that the evidence CCW either increases or decreases crime on average "seems weak"; the study's model found "some support to the law having a negative (but with a positive trend) effect on property crimes, and a small but positive (and increasing) effect on violent crimes".  The Washington Post fact-checker concluded that it could not stated that CCW laws reduced crime, as the evidence was murky and in dispute. 
A study of eight years of Texas data found that concealed handgun licensees were much less likely to be convicted of crimes than were nonlicensees. The same study found that licensees' convictions were more likely to be for less common crimes, "such as sexual offenses, gun offenses, or offenses involving a death."  This is also in line with a 1997 study researching county level data from 1977 to 1992 concluding that allowing citizens to carry concealed weapons deters violent crimes and it appears to produce no increase in accidental deaths. 
A 2018 study in The Review of Economics and Statistics found that the impact of right-to-carry laws was mixed and changed over time. RTC laws increased some crimes over some periods while decreasing other crimes over other periods. The study suggested that conclusions drawn in other studies are highly dependent on the time periods that are studied, the types of models that are adopted and the assumptions that are made. 
A 2011 article co-authored by Stanford Law professor John J. Donohue found that aggravated assaults increase when concealed carry laws are adopted.  A 2017 study in the American Journal of Public Health found that "shall-issue laws" (where concealed carry permits must be given if criteria are met) "are associated with significantly higher rates of total, firearm-related, and handgun-related homicide" than "may-issue laws" (where local law enforcement have discretion over who can get a concealed carry permit).  In a 2017 article in the journal Science by Donohue and Duke University economist Philip J. Cook, they write that "there is an emerging consensus that, on balance, the causal effect of deregulating concealed carry (by replacing a restrictive law with an RTC law) has been to increase violent crime".  Donohue and Cook argue that the crack epidemic made it difficult to determine the causal effects of CCW laws and that this made earlier results inconclusive; recent research does not suffer the same challenges with causality. 
In 1996, economists John R. Lott, Jr. and David B. Mustard analyzed crime data in all 3,054 counties in the United States from 1977 to 1992, finding counties that had shall-issue licensing laws overall saw murders decrease by 7.65 percent, rapes decrease by 5.2 percent, aggravated assaults decrease by 7 percent and robberies decrease by 2.2 percent.  The study was widely disputed by numerous economists, including Georgetown University Professor Jens Ludwig, Daniel Nagin of Carnegie Mellon University and Dan A. Black of the University of Chicago. Black and Nagin, in The Journal of Legal Studies, said of the Lott-Mustard study, "once Florida is removed from the sample, there is no longer any detectable impact of right-to-carry laws on the rates of murder and rape". 
A Texas A&M study that looked at issuance rates of concealed-carry permits and changes in violent crime by county-level in four shall-issue states found no increases or decreases in violent crime rates with changes in permit issuances.  
In 2016 FBI analyzed 40 "active shooter incidents" in 2014 and 2015 where bystanders were put in peril in on-going incidents that could be affected by police or citizen response. Six incidents were successfully ended when citizens intervened. In two stops citizens restrained the shooters, one unarmed, one with pepper spray. In two stops at schools, the shooters were confronted by teachers: one shooter disarmed, one committed suicide. In two stops citizens with firearms permits exchanged gunfire with the shooter. In a failed stop attempt, a citizen with a firearms permit was killed by the shooter.  In 2018 the FBI analyzed 50 active shooter incidents in 2016 and 2017. This report focused on policies to neutralize active shooters to save lives. In 10 incidents citizens confronted an active shooter. In eight incidents the citizens stopped the shooter. Four stops involved unarmed citizens who confronted and restrained or blocked the shooter or talked the shooter into surrender. Four stops involved citizens with firearms permits: two exchanged gunfire with a shooter and two detained the shooter at gunpoint for arrest by responding police. Of the two failed stops, one involved a permit holder who exchanged gunfire with the shooter but the shooter fled and continued shooting and the other involved a permit holder who was wounded by the shooter. "Armed and unarmed citizens engaged the shooter in 10 incidents. They safely and successfully ended the shootings in eight of those incidents. Their selfless actions likely saved many lives." 
- American gun ownership
- Concealed carry
- Defensive gun use
- Gun control
- Gun politics in the United States
- Overview of gun laws by nation
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790.01 Carrying concealed weapons. – (1) Except as provided in subsection (4), a person who carries a concealed weapon or electric weapon or device on or about his or her person commits a misdemeanor of the first degree, punishable as provided in s. 775.082 or s. 775.083. (2) A person who carries a concealed firearm on or about his or her person commits a felony of the third degree, punishable as provided in s. 775.082, s. 775.083, or s. 775.084. (3) This section does not apply to a person licensed to carry a concealed weapon or a concealed firearm pursuant to the provisions of s. 790.06. (4) It is not a violation of this section for a person to carry for purposes of lawful self-defense, in a concealed manner: (a) A self-defense chemical spray. (b) A nonlethal stun gun or dart-firing stun gun or other nonlethal electric weapon or device that is designed solely for defensive purposes. (5) This section does not preclude any prosecution for the use of an electric weapon or device, a dart-firing stun gun, or a self-defense chemical spray during the commission of any criminal offense under s. 790.07, s. 790.10, s. 790.23, or s. 790.235, or for any other criminal offense.
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(3)(a) “Concealed weapon” means any dirk, metallic knuckles, slungshot, billie, tear gas gun, chemical weapon or device, or other deadly weapon carried on or about a person in such a manner as to conceal the weapon from the ordinary sight of another person. (b) “Tear gas gun” or “chemical weapon or device” means any weapon of such nature, except a device known as a “self-defense chemical spray.” “Self-defense chemical spray” means a device carried solely for purposes of lawful self-defense that is compact in size, designed to be carried on or about the person, and contains not more than two ounces of chemical.
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This section lacks ISBNs for the books listed in it. (June 2017)
- 1997 John Lott and David Mustard, " Crime, Deterrence, and Right-to-Carry Concealed Handguns," Journal of Legal Studies.
- 1998 Dan Black and Daniel Nagin, " Do Right-to-Carry Laws Deter Violent Crime?" Journal of Legal Studies.
- 1998 John Lott, " The Concealed-Handgun Debate." Journal of Legal Studies.
- 1998 John Lott, More Guns, Less Crime (U Chicago Press).
- 2000 John Lott, More Guns, Less Crime, Second Edition (U Chicago Press).
- 2003 Ian Ayres and John Donohue, "Shooting Down the ‘More Guns, Less Crime’ Hypothesis, Stanford Law Review.
- 2003 Florenz Plassmann and John Whitley, "Confirming ‘More Guns, Less Crime," Stanford Law Review.
- 2003 Ian Ayres and John Donohue, "The Latest Misfires in Support of the ‘More Guns, Less Crime’ Hypothesis," Stanford Law Review.
- 2003 John Lott, The Bias against Guns (AEI).
- 2004 John Donohue. " Guns, Crime, and the Impact of State Right-to-Carry Laws" Fordham Law Review 73 (2004): 623.
- 2005 Robert Martin Jr., & Richard Legault, " Systematic Measurement Error with State-Level Crime Data: Evidence From the "More Guns, Less Crime" Debate," J. Research in Crime & Delinquency
- 2008 Carlisle E. Moody and Thomas B. Marvell. " The Debate on Shall-Issue Laws," Econ Journal Watch 5.3: 269–93.
- 2009 John Donohue and Ian Ayres. " More Guns, Less Crime Fails Again: The Latest Evidence from 1977–2006" Econ Journal Watch 6.2: 218–38.