Keith Daniel Williams was born on June 6, 1947, in Pittsburg, California. His early life was marked by hardship and instability. Born prematurely to a single mother who drank during pregnancy, Williams’ twin brother miscarried, leaving him frail and often sick. He struggled with eating and sleeping, and his mother remarried in 1948 to a man who treated him harshly. According to testimony later given in court, even the family dog was treated with more care than young Keith.

The Williams family moved frequently, living in motels, tents, makeshift shelters, and even a converted chicken coop. His childhood instability compounded his fragile health. As a teenager, he endured multiple traumatic accidents, including being struck by an irrigation pipe in a traffic collision and a motorcycle crash that left him in a coma. These injuries reportedly caused memory loss, headaches, blackouts, and seizures.

Williams left school early and began working as a ranch hand. By the early 1960s, he was already developing a criminal record, including burglary, auto theft, and attempted forgery. He spent time at the California Youth Authority, where he allegedly experienced violence that worsened his mental state.

During the 1970s, his life spiraled further. He was diagnosed with bipolar disorder, engaged in heavy drinking and drug use, and attempted suicide at least once. In 1976, he stabbed his best friend in a violent outburst and soon after checked into a psychiatric hospital. By 1977, he had been arrested 11 times and spent nearly a third of his life in custody. Williams married twice and had children, but both marriages ended in divorce. By the time of the murders, he was living in Corning, California, trying to survive with odd jobs.

In September 1978, Williams met Robert Leslie Tyson, 26, while doing remodeling work. The two quickly became partners in both petty crime and odd jobs. Together they stole goods, including a firearm, from an employer. Williams kept the gun and later used it in a crime spree that escalated into murder.

On October 6, 1978, Williams met Miguel Vargas (31) and his girlfriend Lourdes Meza (25) during a yard sale organized by Tyson’s wife. Vargas owned a 1973 Plymouth Road Runner and agreed to sell it to Williams for $1,500. Williams gave Vargas a stolen check from a prior burglary, knowing it would bounce. When Vargas refused to release the car until the check cleared, Williams began plotting to rob and kill him.

On the night of October 8, 1978, Williams and Tyson drove to Vargas’ home in Merced, California. Inside were Vargas, Meza, and a visitor, Salvador Macias (41). The men initially pretended to negotiate the car purchase and discuss selling a gun. When the other guests left, Williams and Tyson returned armed.

Williams forced Vargas upstairs at gunpoint. There, he shot both Vargas and Macias twice each, execution-style. He then looted the house, taking guns, Meza’s purse, and the forged check. Tyson, tasked with killing Meza, failed to pull the trigger. Williams took over, shooting her before abducting her alive.

The two men drove off in Vargas’ car, with Williams repeatedly raping Meza in the backseat during the ride. After more than an hour, they stopped in a remote area near Tuolumne City, where Williams shot Meza four times and left her body naked in a field.

The next morning, a family member discovered Vargas and Macias dead in the Merced home. Their bodies were found face down, shot in the back of the head. Five days later, Tyson surrendered to police and led them to Meza’s remains. She had been shot four times. Tyson testified that Williams had killed all three victims.

Williams fled the state but was arrested on November 24, 1978, in Kingman, Arizona. He confessed on videotape to the triple murder, though he denied raping Meza, claiming the sex had been consensual.

Williams was indicted on three counts of murder. At his trial in March 1979, he pleaded not guilty by reason of insanity. Tyson testified against him as the prosecution’s key witness. On April 6, 1979, the jury convicted Williams of all three murders. He was acquitted of rape due to decomposition of Meza’s body, which prevented confirmation. On April 10, 1979, the jury found him sane at the time of the crimes. On April 13, Judge Donald Fretz sentenced him to death.

Tyson, as an accomplice, received three concurrent 25-to-life sentences.

Williams pursued numerous appeals. He argued that his mental health issues and poor legal defense undermined his trial. His case reached the California Supreme Court in 1988, which upheld his conviction. The U.S. Supreme Court denied his appeal later that year. Subsequent federal petitions failed, and by 1995, his final appeals had been exhausted.

On March 11, 1996, an execution date of May 3, 1996 was set. Governor Pete Wilson denied clemency on April 24, 1996.

At 12:03 a.m. on May 3, 1996, Williams was strapped to a gurney in the execution chamber at San Quentin State Prison. He was executed by lethal injection and pronounced dead at 12:08 a.m. His last meal included fried pork chops, baked potato, asparagus, salad with blue cheese dressing, apple pie, and whole milk. He had no last words.