Dalton Prejean was born on December 10, 1959, in Lafayette, Louisiana. He was the second of four children in his family. When Dalton was just two weeks old, his parents decided to send him to live with his aunt and uncle in Houston, Texas. He grew up there and did not learn about his real parents until he was eleven years old. This information came when his father left his mother and went to live in Houston. Dalton’s aunt felt it was necessary to inform him that he was not her child.

After learning this, Dalton began to have issues, which led to his return to live with his mother in Lafayette. Once back in Lafayette, he began skipping school. His mother, worried about his future, insisted that he be committed to the Louisiana Training Institute in March 1972 due to his truancy. He stayed there for seven months after which he faced more troubles with the law, including charges of burglary and theft.

In March 1974, Dalton was placed in the Lafayette Juvenile Youth Authority, a residential program for young delinquents. However, he ran away from the facility after a month. When he returned, his commitment was ended, and he was released on probation to his mother.

On July 2, 1977, Dalton Prejean was involved in a fatal incident that took place in Lafayette Parish, Louisiana. Dalton and three companions had spent the night drinking at various establishments. They got into a 1966 Chevrolet, with Dalton driving, and left Roger's Nite Club early in the morning. The car had defective taillights, which caught the attention of Louisiana State Trooper Donald Cleveland. He signaled for the Chevrolet to stop.

With Dalton behind the wheel, he and his brother Joseph quickly tried to switch places because Dalton was driving without a license. Trooper Cleveland noticed the switch and instructed all the occupants to exit the vehicle. He began to search Joseph Prejean while telling the others to get back inside the car. Dalton, feeling protective of his brother, expressed his discontent with how Trooper Cleveland was handling the situation.

In that moment, Dalton retrieved a loaded .38 caliber revolver from under the car seat. He approached Trooper Cleveland with the gun hidden against his leg. Without any warning, Dalton fired at the officer. Trooper Cleveland was hit by two bullets and was subsequently killed. After the shooting, Dalton and his companions fled the scene but were apprehended a few hours later by law enforcement.

Dalton faced trial for his actions, which started on May 1, 1978. He was found guilty of first-degree murder and the jury recommended the death penalty. Appeals followed, citing his low IQ and mental health issues as factors in his case. His appeal reached the US Supreme Court but was ultimately dismissed. Dalton Prejean was executed on May 18, 1990, in the electric chair at Louisiana State Penitentiary, also known as Angola.