Jemison played quarterback and defensive back at McAdory High School, graduating in 2008. He was named a Super All-Metro player by the Birmingham News as a junior and was heavily recruited for his athleticism, signing with Auburn University in February 2008. He was dismissed from the team before the 2009 season began, then later signed with Grambling State University and played in 2010 for Pearl River Community College. In 2011 Jemison was signed to the Canadian Football League's Calgary Stampeders roster, but released before the start of the 2011 season.
Jemison was charged with capital murder in the September 19, 2011 shooting of Jeremy Jamal Williams in Bessemer. Prosecutors allege that Jemison and Justin Hollon approached Williams to purchase drugs and shot and robbed him after an argument broke out. Jemison's attorney, Charles Salvagio, claimed that the three were friends and the shooting was accidental.
Before Jemison's case went to trial, he was involved in another violent incident in October 2014 where witnesses saw three armed men hogtie a man, stuff him into the trunk of an Audi, and drive off. The victim was accused by his abductors of stealing money and drugs. They took him to a house on Morgan Road where they opened the trunk for the victim's girlfriend's father, threatening to kill him unless he took them to the stolen items. From there they moved the victim to the car's back seat and proceeded to the vicinity of Pocahontas Road, by which time Jefferson County Sheriff's deputies were following the suspect car. The victim was released and two suspects, Jemison and Gregory Miller, were arrested and charged.
During a hearing held to determine if his bond on the murder charge would be revoked because of the additional charges, Jemison's attorneys argued that the incident was a dispute between relatives and that Jemison's involvement was his attempt to settle the dispute peacefully. During the hearing, however, Jemison was given a rapid urine test which indicated that he had marijuana in his system. His bond was thus revoked without addressing the other charges.
In January 2015 Jemison pleaded guilty to manslaughter in Williams' death and was sentenced to 17 years in prison. The other charges from 2014 were dropped as part of the plea bargain.
- Debro, Anita (October 20, 2011) "Former McAdory, Auburn football player Marcus Jemison seeks bond on capital murder charge." The Birmingham News
- Robinson, Carol (October 31, 2014) "2 charged in Bessemer kidnapping where victim was hogtied and stuffed in trunk." The Birmingham News
- Faulk, Kent (November 5, 2014) "Bessemer man arrested in alleged Morgan Road kidnapping was out on bond in 2011 capital murder case." The Birmingham News
- Faulk, Kent (January 28, 2015) "Bessemer man faced death sentence in fatal shooting, gets 17 years with manslaughter plea." The Birmingham News