SAN DIEGO -- A schizophrenic ex-con accused of using a stolen flatbed truck to run down and kill a pursuing San Diego police motorcycle officer is mentally incompetent to stand trial, a judge ruled Wednesday.

Superior Court Judge Howard Shore made the finding after reviewing reports from three psychiatrists, all of whom said Kevin Gerard Williams, (pictured, left), did not understand the charges against him and could not assist his attorneys in his defense.

The 37-year-old defendant, who was diagnosed with schizophrenia at age 13, will be sent to Patton State Hospital for no longer than three years, said prosecutor David Hendren.

The criminal charges against Williams were suspended Sept. 11, when his attorneys questioned his mental competency, but could be reinstated if the defendant is deemed competent to stand trial in the June 26 killing of Officer Terry Bennett, (pictured, right).

"I'm not going to make any predictions," Hendren said. "Obviously, we'd like to bring this to trial as soon as we can."

Hendren said he told Bennett's widow of the doctors' findings.

Deputy Public Defender Richard Gates told reporters that his client remembers the crash that killed Bennett, but his thoughts are scattered and disorganized.

"Mr. Williams has a recollection," Gates said. "He can't hold a thought for more than a few seconds."

Gates said Williams -- a homeless illiterate and poor man -- often rambles incoherently and is fixated on religious delusions.

The attorney said doctors at Patton will try to temper Williams' mental disease with medications, but it will always be there.

"You can't cure his mental illness," Gates said. "He is always going to be schizophrenic."

Gates said Williams should never have been allowed out in the community.

"He should have been in a locked psychiatric facility his adult life," the attorney said.

Prosecutors said earlier that Williams has a long criminal history and had twice before led officers on chases.

The defendant has six prior felony convictions and has been to prison three times, prosecutors said. The defendant's latest stint in prison was for a 1997 robbery, for which he served 18 months, according to court records.

Hendren said Bennett started chasing Williams in Encanto. The fleeing GMC flatbed truck was filled with tools and a generator that the defendant had allegedly stolen earlier, the prosecutor said.

Williams made a hard U-turn about 12:30 p.m. and used the truck as a "battering ram to pulverize the defenseless officer" into a fence, the prosecutor said.

A dozen blocks away, Williams ditched the truck after one tire went flat. When a pedestrian heard sirens and asked him if he was running from the police, the defendant reportedly responded, "yeah." He was arrested a short time later.

The defendant could face the death penalty if convicted of murder, auto theft, evading police with reckless driving, evading police resulting in death, two counts of hit-and-run and special circumstance allegations of lying in wait, killing Bennett in the line of duty and killing the officer to avoid arrest.