Keith Daniel Williams was born prematurely on June 6, 1947, in Pittsburg, California. His early life was marked by instability, poverty, and severe neglect. His mother, who consumed alcohol during her pregnancy, lost his twin during a miscarriage. After marrying another man in 1948, she brought Keith into a household where he was treated poorly—his mother later stated the family dog received better care than he did. The family’s living conditions were often dire, with homes ranging from tents to a converted chicken coop.

Williams suffered multiple head injuries as a teenager, including a serious motorcycle accident that left him in a coma. These incidents reportedly contributed to severe memory issues, headaches, seizures, and behavioral changes. Dropping out of high school, he began working as a ranch hand but quickly fell into a cycle of criminality, drug use, and alcoholism. His early rap sheet included burglaries, auto theft, and forgery. By his twenties, he had spent a third of his life incarcerated and had undergone psychiatric treatment for bipolar disorder. Despite two failed marriages and fathering children, his life remained unstable. In 1976, he stabbed his best friend and attempted suicide, later checking himself into a psychiatric hospital in San Diego. By 1977, he had accumulated eleven arrests and struggled to reintegrate into society. At the time of the murders in 1978, Williams was living in Corning, California, near his family.

The violent crimes for which Keith Williams would ultimately be executed occurred in October 1978 in Merced, California. Williams had recently met 26-year-old Robert Tyson while working on a remodeling job. The two quickly formed a partnership, engaging in petty crimes and burglaries, including stealing a firearm from their employer. One week later, Williams, Tyson, and others attempted to drive to Modesto but were stranded due to a car breakdown. Spotting a camper nearby, Williams and Tyson robbed the occupants at gunpoint and pawned the stolen goods. One stolen item was a checkbook, which Williams retained for later use.

On October 6, 1978, Williams met Miguel Vargas and Lourdes Meza at a yard sale organized by Tyson’s wife. Williams offered to buy Vargas’ 1973 Plymouth Road Runner for $1,500 using one of the stolen checks. Vargas, cautious, refused to hand over the car’s title until the check cleared. Williams, realizing the check was useless, devised a plan to rob Vargas, whom he had seen carrying a large amount of cash.

On October 8, 1978, Williams and Tyson visited Vargas’s home under the pretense of finalizing the car sale. When only Vargas, Lourdes Meza, and a third man named Salvador Macias remained, Williams and Tyson returned with weapons. Williams took the lead, shooting Vargas and Macias twice each in the head. He stole two guns, Meza’s purse, and the voided check. Tyson, unable to kill Meza, watched as Williams abducted her. During the car ride, Williams raped her, then later drove to a remote location near Tuolumne City, where he shot her four times and left her naked body in a field.

Tyson turned himself in to police five days later and led them to Meza’s body. Williams was arrested on November 24, 1978, in Arizona, where he confessed to the murders on video. He was charged with three counts of murder and pleaded not guilty by reason of insanity. His trial began in March 1979, and on April 6, he was found guilty. Although Williams confessed to raping Meza, he was acquitted of rape due to the decomposition of her body, which made forensic confirmation impossible. He was declared sane on April 10 and sentenced to death on April 13.

Over the next 17 years, Williams filed numerous appeals, challenging the competency of his original legal defense and raising mental health issues. All appeals were ultimately denied, and Governor Pete Wilson refused clemency in April 1996. On May 3, 1996, Keith Daniel Williams was executed by lethal injection at San Quentin State Prison. His last meal included pork chops, baked potato, asparagus, apple pie, and milk. He had no final words.