SAN DIEGO -- A parolee accused of stabbing a couple in Hillcrest for no apparent reason while he was on parole for assaulting a police officer was convicted Monday of assault with a deadly weapon but acquitted of torture charges.

In addition to the two assault counts, the six-man, six-woman jury convicted 32-year-old Jared Jacobson of allegations that he used a knife and caused great bodily injury in the Feb. 4, 2007, attack on Caroline and Donald Stewart.

Jacobson pleaded not guilty by reason of insanity, so a hearing will now be held on whether the defendant should be imprisoned or committed to a state mental hospital. The proceeding is set to start on Tuesday, but may be delayed due to scheduling issues involving the lawyers in the case.

In her opening statement at trial, Deputy District Attorney Melissa Vasel said Jacobson came up behind the couple while they were walking and stabbed them, then sat on the curb and watched them bleed.

"They never even saw it coming," Vasel said.

After his arrest, Jacobson told police, "it's so easy to shank people"; "that was (expletive) fun"; and "it (the knife) went in like butter," Vasel told the jury.

The defendant's attorney, Troy Britt, told the jury that his client is schizophrenic and did not intend to hurt anyone.

Britt said the mental health system failed Jacobson, who first saw a psychiatrist when he was 14 1/2 and later traveled from Hawaii to New York to attempt suicide by jumping off a bridge.

On Jan. 31, 2007, Jacobson left a group mental health session because he thought people were talking about him and later tried to commit suicide again, his attorney said.

A week before the Stewarts were stabbed, Jacobson was taken to a county mental health facility with slash marks on his arm, and the next day a psychiatrist diagnosed him as a chronic paranoid schizophrenic, Britt said.

Jacobson went back to County Mental Health for three days, and his psychiatrist tried to get him committed because he knew was going to do something violent, Britt told the jury.

He was released Feb. 2, two days before the attack on the Stewarts, Britt said.

Testimony in the sanity phase is expected to last two days in the courtroom of Judge Melinda Lasater. If the jury finds that Jacobson was sane, he could be sentenced to as much as 15 years in prison.