A San Jose man had “malice in his heart” when he walked into the Paso Robles Laundromat and stabbed a stranger 30 times, a prosecution witness testified Wednesday.

In the trial of John F. Woody Jr., the defense has suggested that Woody’s mental illness guided him when he killed 46-year-old Martin McWilliams on March 6, 2011. The District Attorney’s Office, however, maintains that Woody was in control of his actions. To support that, Deputy District Attorney Matt Kerrigan called a “star” witness — Kris Mohandie, a police and forensic psychologist who has worked several high-profile cases and appeared on several national TV shows.

Not only did Woody exhibit purposeful behavior on the night of the killing, Mohandie testified, but he also exaggerated the impact his mental illness had on his actions.

“He absolutely has a serious mental disorder,” Mohandie testified. But, he added, “You can still have a mental disorder and exaggerate those symptoms.”

After the stabbing, Woody made several bizarre statements to police. Based on psychological tests he gave Woody in July, Mohandie said, “I think he’s overplaying it.”

While no other mental health experts — including those who evaluated Woody prior to the killing — have accused Woody of exaggerating his symptoms, experts have disagreed over his exact diagnoses. While they agree he has some form of schizophrenia, some have said he also has an antisocial personality disorder.

Antisocial personality disorder is viewed as a character flaw and not a mental illness.

It’s that diagnosis, the prosecution will argue, that led Woody to kill McWilliams as he watched television and washed his family’s clothing inside the Paso Robles Laundromat.

To support the antisocial personality claim, Mohandie pointed to several incidents in Woody’s past, including cruelty to animals, fights with police — including two that ended with Woody being tasered — vandalism and deceitfulness. As a middle school student, Mohandie testified, Woody was a bully who once used a metal pipe in a fight. As an adult, he once hit his mother with a broom after she told him to take his medication.

On the night of the stabbing, Mohandie said, Woody acted like a hunter, proven by the fact that Woody staked out the establishment to make sure only McWilliams was there.

As he confronted McWilliams, he hid the knife in his jacket, then quickly began stabbing him.

“He had malice in his heart when he went in there and had a desire to hurt somebody,” Mohandie said.

Other actions — including fleeing the scene of the crime and calling a bank to get money — suggest purposefulness and goal-oriented behavior.

He may have intended to rob McWilliams, he said.

“But for the antisocial personality disorder, we wouldn’t have necessarily gone down that path,” he said.

Defense attorney Ken Cirisan has suggested that Woody — who had been in multiple mental institutions prior to the killing — was hearing several critical voices in his head that night. When he paced in front of the Laundromat, Cirisan suggested, he was looking to find the source of the voices.

During testimony Tuesday, psychologist Carolyn Murphy said Woody was a “longtime schizophrenic” who was tormented by those voices.

“He was hearing voices, and he wanted the voices to stop,” she said.