Robert Wayne Harris was born on February 28, 1972, in Dallas County, Texas. His early life was marked by tragedy. When Harris was eight years old, he witnessed his father kill his mother and then take his own life. This traumatic event deeply affected him. After this, he was sent to live with various relatives.

As he grew older, Harris faced many challenges. He developed a stutter and had trouble in school. Because he struggled with his studies, he was placed in special education classes. He experienced bullying and had conflicts with both teachers and students. Harris dropped out of school in the ninth grade.

Despite these challenges, he earned his GED when he turned 18. Throughout his youth, he was diagnosed with aggressive conduct disorder. He often had physical confrontations with others, which added to his difficulties. At the age of 15, he committed various offenses, including assault and burglary, which led him to spend time in a juvenile correctional facility.

On November 29, 1999, Robert Wayne Harris abducted and killed Sandra Scott, a 37-year-old woman. He suspected her of stealing money from him. Although he was initially questioned about her disappearance, he was not charged. When police found Sandra's truck, only the keys were left inside, and other belongings were missing.

On March 15, 2000, Harris was fired from his job at Mi-T-Fine Car Wash after he exposed himself to a female customer. Just days later, on March 19, he borrowed a car from a friend and obtained a pistol from another acquaintance.

On March 20, 2000, before the car wash opened, Harris forced three employees into the office: manager Dennis Lee, assistant manager Augustin Villasenor, and cashier Rhoda Wheeler. He ordered them to open the safe, then shot them and slit Dennis Lee's throat. When three other employees arrived, he forced them to the floor and shot them as well. Two of them, Benjamin Villasenor and Roberto Jimenez, were killed, while another survived but suffered permanent disabilities. All the victims were shot once in the back of the head.

Afterward, an employee named Jason Shields came to the car wash and found the victims. When he saw Harris, who claimed to have stumbled upon the scene, he ran to a nearby donut shop and called the police. Harris followed him there and briefly talked to a 911 operator before fleeing the scene. He stole about $4,000 during the robbery.

Harris returned the car he borrowed and told his friend he had discovered the bodies. He then disposed of evidence at a friend’s house, bought new clothes, and checked into a motel. The next day, he was arrested at another friend's home. During questioning, Harris confessed to killing both Sandra Scott and the victims at the car wash.

He was charged with capital murder for the car wash shootings. In September 2000, a jury found him guilty after deliberating for just 11 minutes. During sentencing, Harris' lawyers requested a life sentence due to his psychological issues. However, the jury recommended the death penalty after deliberating for two hours.

While on death row, Harris's lawyers argued that he was mentally disabled, but experts concluded that he was not. On September 20, 2012, Robert Wayne Harris was executed by lethal injection. His last words expressed love for his friends and family. He is buried at Captain Joe Byrd Cemetery.