He helped mow down a cop in a hail of machine gun fire as the officer picked up his son from day care.

For his part in the 1985 cop killing in Canoga Park, Voltaire Alphonse Williams should languish behind bars for life, family and associates of the victim said.

Williams, who has served 24 years in prison for conspiring to kill Los Angeles police Detective Thomas C. Williams - no relation - faces a state parole board hearing Friday at Solano State Prison in Vacaville.

"We've been on a major campaign to get his parole denied," said widow Norma Williams, formerly of West Hills and now living out of state. "I hate him. I absolutely despise him. He might as well have pulled the trigger." The 42-year-old Tom Williams was shot by Daniel S. Jenkins on Halloween 1985 just hours after the detective had testified against him during a robbery-assault trial. It was the third attempt on Williams' life.

As the final hitman in the complicated assassination plot, Jenkins would be sentenced to death; Ruben A. Moss, his right-hand man, would get life in prison. And Voltaire Williams, one of six men accused in the policeman's death, would be sentenced to 25 years to life. His last parole hearing was in 2006. Williams' court-appointed attorney did not immediately return calls Wednesday.

Prosecutors and police unions across the nation have once again objected to his release.

"This was callous. This was calculating. This was intended to murder Detective Williams to prevent him from doing his job," said Paul Weber, president of the Los Angeles Police Protective League, the union representing nearly 10,000 L.A. officers. "They murdered him in front of his son, in public view."

He said Voltaire Williams "should spend the rest of his life in prison ... he should stay in there until the day he dies." Tom Williams, father of two, was a 6-foot-2 Irish cop with a zest for detective work. A 13-year veteran who had turned down an appointment at West Point to join the LAPD, he had hoped to work homicide cases.

Voltaire Williams, a self-proclaimed prizefighter who was then 26, was hired by Jenkins to kill the cop for $2,000, but could not. Prosecutors said Williams then recruited others for the slaying, including one hitman paid $10,000 by Jenkins who balked at shooting the policeman in front of his 6-year-old son. They had also staked out Williams' home and were prepared to kill his wife and kids.

On the day the jury in his robbery trial began deliberating on Jenkin's guilt, the North Hollywood mastermind drove to Faith Baptist Church school where Williams' son Ryan attended. Outside the school, he cut down the detective with bursts from a Mac-10 machine pistol. Williams was struck eight times. His truck and the day-care were riddled with bullets.

His killer would later boast, "I got down and did it myself," according to court testimony. For protecting his son during the shooting, Williams would be awarded a posthumous Medal of Valor.

His daughter, then a 17-year-old student at Canoga Park High School, would for years attend funerals of slain police officers and now struggles with post-traumatic stress disorder. His son struggles, too, and still harbors guilt over not being able to save his dad, his mother said.

She said Halloween, and Williams' parole hearings, have been especially painful. "My children have suffered much through these past years," said Williams, in a letter to the state parole board. "They are adults now, but carry with them the pain and horror of that day.

"It has been over 24 yrs. since that horrendous day ... and nothing has ever 'paroled' us from the anguish, pain and suffering we've endured."