Robert Glen Coe was born on April 15, 1956, in Hickman, Kentucky. He grew up in a low-income family. His early life was marked by difficulties and trauma. Coe attended Gleason School in Gleason, Weakley County, Tennessee.

Coe's home life was troubled. His father often drank too much alcohol and displayed inappropriate behavior in front of Coe and his younger sister. This included acts that made both children uncomfortable. Coe's father also forced them to witness troubling sexual acts involving his oldest daughter.

On September 1, 1979, Cary Ann Medlin, who was eight years old, was riding her bicycle with her stepbrother in Greenfield, Tennessee. Robert Glen Coe approached them and pretended to know her father. He asked for directions, and Cary got into his car to help. Unfortunately, she was never seen alive again.

When Cary went missing, the community rallied together to search for her. People looked for Cary and for Coe, who had been the last person seen with her. Sadly, her body was discovered the next day on the outskirts of town. An autopsy later confirmed that she had been sexually assaulted.

Coe had a troubled past filled with drug abuse and mental health issues. After the murder, he confided in family members that he had killed someone. Some family members tried to help him flee by buying him a bus ticket to Georgia. However, another family member contacted the police. Coe was captured at the bus station on September 4.

Once in custody, he confessed to the crime three days later. His confession revealed that he had taken Cary to a secluded location. He described engaging in sexual acts while she watched. Coe noted that when Cary repeatedly said, "Jesus loves you," it made him angry. He then decided to kill her. He choked her until she turned blue and then pulled out a pocketknife and stabbed her in the throat. This resulted in her quickly bleeding to death.

In 1981, Coe was sentenced to death for his crimes. He remained on death row for years. Finally, on April 19, 2000, Coe was executed by lethal injection at the Riverbend Maximum Security Institution in Nashville, Tennessee. He was the first person to be executed in Tennessee since the reinstatement of the death penalty in 1976.