When the prosecution seeks the death penalty, the sentence is decided by the jury and must be unanimous. If the jury recommends death, it is required to record what it considers the "aggravating circumstances" about the crime that led it to that decision. 
The following crimes are punishable by death in Mississippi:
- Murder with one of the following aggravating factors: 
- It was committed by a person under sentence of imprisonment.
- The defendant was previously convicted of another capital offense or of a felony involving the use or threat of violence to the person.
- The defendant knowingly created a great risk of death to many persons.
- It was committed while the defendant was engaged, or was an accomplice, in the commission of, or an attempt to commit, or flight after committing or attempting to commit, any robbery, rape, arson, burglary, kidnapping, aircraft piracy, sexual battery, unnatural intercourse with any child under the age of 12, or nonconsensual unnatural intercourse with mankind, or felonious abuse or battery of a child, or the unlawful use or detonation of a bomb or explosive device.
- It was committed for the purpose of avoiding or preventing a lawful arrest or effecting an escape from custody.
- It was committed for pecuniary gain.
- It was committed to disrupt or hinder the lawful exercise of any governmental function or the enforcement of laws.
- It was committed to influence the policy of a governmental entity by intimidation or coercion, or to affect the conduct of a governmental entity by mass destruction or assassination.
- It was especially heinous, atrocious or cruel.
- It was committed to intimidate or coerce a civilian population.
The laws on the books in Mississippi also provide the death penalty for aircraft hijacking under Title 97, Chapter 25, Section 55 of the Mississippi Code, but in 2008, the U.S. Supreme Court ruled in Kennedy v. Louisiana, that the death penalty is unconstitutional when applied to non-homicidal crimes against the person. However, the ruling meant that crimes "against the state" such as treason or terrorism would not likely be unconstitutional. Therefore, the offence of aircraft hijacking would likely be considered a crime against the state in Mississippi because it is widely considered to be an act of terrorism and the death penalty in this case may be constitutional.
The method of execution is lethal injection.  Executions take place in the execution chamber, built in 2002, adjacent to the gas chamber, which is no longer in use, but continues to sit there to this day.
Currently executions occur at the Mississippi Department of Corrections (MDOC) Mississippi State Penitentiary (MSP, also known as "Parchman") in Sunflower County, Mississippi.  The condemned prisoner is moved into a holding cell adjacent to the execution room in Unit 17, the location of the execution chamber, in the Mississippi State Penitentiary from his or her death row unit 48 hours prior to the execution. The state places MSP on emergency lockdown status 24 hours before the execution. At 12:00 PM a media center at Parchman opens. At 3:00 PM the condemned's attorney of record and chaplain are permitted to visit him or her. At 4:00 PM the prisoner received his or her last meal; he or she may shower at that time. At 4:30 PM, if the condemned desires, MDOC clergy may visit him or her. At 5:30 witnesses to the execution are transported to Unit 17. At 6:00 PM officials move the condemned from the holding cell to the execution chamber. At the same time the witnesses enter the designated observation areas. At 7:00 PM the state conducts a post-execution briefing with media witnesses. At 8:30 PM the state closes its media center. 
The State of Mississippi used hanging as its method of execution for much of its history.  From the earliest recorded execution in 1818 through 2004, records indicate that the state executed a total of 794 people. Of these, the great majority were black males, who account for 639 of recorded executions. 
Around the time of the 1901 opening of the Mississippi State Penitentiary (Parchman Farm), Sunflower County residents objected to having executions performed at MSP because they feared that Sunflower County would be stigmatized as a "death county." Therefore, the State of Mississippi originally performed executions of condemned criminals in their counties of conviction.  When, in 1940, Mississippi's state legislature decided to change the state's method of execution to electrocution, while continuing to conduct executions in the county of conviction, a portable electric chair was developed and fabricated for the state's use.  On October 11, 1940, the state's first execution of a condemned prisoner by electrocution occurred; Hilton Fortenberry was electrocuted in his county of conviction, Jefferson Davis County. The state moved the electric chair from county to county, using it to kill condemned prisoners in their counties of conviction.  Mississippi and Louisiana were the only U.S. states to use a portable electric chair. 
Around the 1950s residents of Sunflower County were still opposed to the concept of housing the execution chamber at MSP. In September 1954, Governor Hugh L. White called for a special session of the Mississippi Legislature to discuss the application of the death penalty.  During that year, a gas chamber serving as an execution chamber was installed at MSP. The gas chamber replaced the portable electric chair which, between 1940 and February 5, 1952, had been moved from county to county to execute condemned prisoners. The first person to die in the gas chamber was Gerald A. Gallego, who was executed on March 3, 1955. 
On July 1, 1984 the Legislature of Mississippi amended §§ 99-19-51 of the Mississippi Code; the new amendment stated that prisoners who committed capital crimes after July 1, 1984 would be executed by lethal injection.  When the Central Mississippi Correctional Facility (CMCF) opened in January 1986, all women who were incarcerated at MSP were moved to CMCF.  The $41 million Unit 32, the state's designated location for male death row inmates, opened in August 1990.   Previously Unit 17 housed Parchman's male death row.  On March 18, 1998 the legislature made another amendment, removing the gas chamber as a method of execution.  The lethal injection table was first used in 2002. 
Since 1976, Mississippi has executed fewer prisoners than six other southern states despite comparable homicide rates. As of March 2013, 21 inmates were executed after 1976.  One critic claims that this stems from the inability of poorer counties to afford legal fees for defendants accused of capital crimes.  Because death penalty cases are subject to a high standard of review—and there is a constitutional requirement for effective assistance of counsel as a matter of Due process of law and subsequent appellate review—this has led to a practical and constitutional impediment to its efficient operations. 
Four prisoners on death row in Mississippi have had their convictions overturned and been found innocent of the original charges. 
- Cabana, Donald A. " The History of Capital Punishment in Mississippi: An Overview." ( Archive) HistoryNow, Mississippi Historical Society. Hosted at the Mississippi Department of Archives & History.
- List of individuals executed in Mississippi
- List of death row inmates in Mississippi
- Crime in Mississippi
- Law of Mississippi
- "§ 99-19-103 - Instructions; aggravating circumstances shall be designated by jury in writing upon recommending death; effect of jury's failure to agree on punishment". law.justia.com. Retrieved June 29, 2016.
- "Mississippi Constitution - SECTION 124". law.justia.com. Retrieved June 29, 2016.
- Mississippi Code § 99-19-101
- " State Prisons." Mississippi Department of Corrections. Retrieved on January 14, 2011.
- "§ 99-19-51 - Manner of execution of death sentence". law.justia.com. Retrieved June 29, 2016.
- " Media Kit Joseph D. Burns Archived 2013-06-03 at WebCite." Mississippi Department of Corrections. 5/8. Retrieved on November 6, 2010.
- " Media Kit Joseph D. Burns Archived 2013-06-03 at WebCite." ( Archive) Mississippi Department of Corrections. 4/8. Retrieved on November 6, 2010.
- Cabana, Donald A. " The History of Capital Punishment in Mississippi: An Overview Archived 2010-10-07 at the Wayback Machine.." Mississippi History Now. Mississippi Historical Society. Retrieved on August 16, 2010.
- " Mississippi and the Death Penalty." Mississippi Department of Corrections. Retrieved on August 12, 2010.
- " A Brief History of the Mississippi Department of Corrections." Mississippi Department of Corrections. Retrieved on July 21, 2010.
- " Prison won't cure overcrowding." The Advocate. September 18, 1990. Retrieved on August 9, 2010. "Hard-core Mississippi prisoners will be housed in a $41 million prison complex that opened last month, but the facility won't come close to providing room for all state inmates, officials say. The complex, called Unit 32, adds more than 15 times the current maximum-security bed space, but it's still not enough."
- Straziuso, Jason. " Miss. prepares chamber for 1st execution since '89." The Advocate. July 14, 2002. News 10B. Retrieved on August 13, 2010. "The execution chamber is lodged in the back of Unit 17 on the Parchman campus. The unit once housed all death row inmates, but its 56 beds are no longer"
- Halperin, Rick. "Execution Statistics Summary -- State and Year". Southern Methodist University. Retrieved 6 April 2013.
- Mitchell, Charlie (November 6, 2005). "Death penalty getting costly in Mississippi: Counties having to foot high bills for defense attorneys". Clarion-Ledger. Archived from the original on February 13, 2006. Retrieved 2010-11-11.
- Innocence Database. Death Penalty Information Center. 2017