A 22-year-old Santa Rosa man believed his father was chiding him about his drug use and accusing him of having an unhealthy relationship with his divorced mother in the moments before he's charged with stabbing him to death.

In a police interrogation video played for jurors Thursday, a frazzled-looking Houston Herczog told detectives he was angered by the accusations from Mark Herczog, 63, who he said confronted him in the kitchen of their Rincon Valley home.

He said he thought his father mocked him about being "replaced" by his mother's boyfriend before they fell into a violent altercation that he declined to describe.

Pressed for details of the clash by Santa Rosa police Detective Stephen Rakoski, Herczog asked for an attorney.

"I mean, I don't know if you want the specifics of it," he said in the interview, conducted four hours after the slaying. "I mean, it's horrible."

Herczog, who has pleaded not guilty by reason of insanity, is accused of stabbing his father more than 60 times in the November 2011 attack. Police said he also bludgeoned his fallen father with a guitar amplifier.

He was arrested after his sister called 911 and he confessed to officers, according to testimony.

Three doctors who examined him said he was suffering a psychotic break at the time and diagnosed him with paranoid schizophrenia.

A doctor hired by the District Attorney's Office disagreed, finding he was in a drug-induced psychosis brought on by taking Adderall, a stimulant he had been stealing from his mother, Marilyn Herczog of Forestville.

Family members countered Herczog had been deteriorating in the year before the slaying and was unable to receive adequate treatment.

In his police interview, Herczog admits taking Adderall from his mother the night of the killing. He said his mother found out and called his father, who was waiting for him when he got home.

In the ensuing confrontation, he said, his father accused him of having an incestuous relationship with his mother. He called it ridiculous, saying she was a much better parent than he was.

"Like he alluded to me and my mom doing things and me being replaced by her boyfriend," Herczog said. "All that ridiculous nonsense.So, like, uh, mocking in it."

When asked what happened next, he said he thought he should talk to a lawyer.

"Because the whole thing doesn't seem real from that point on," he said.

One of the doctors who found him insane, Donald Apostle, testified Thursday that Herczog's mental condition caused him to hear voices and misinterpret what other people were saying.

He said he believed his father was possessed by an evil force that had to be exorcised. The perceived taunts helped push him over the edge.

But prosecutor Bob Waner suggested Herczog might be faking it. Waner questioned Apostle about his own testing that showed Herczog was exaggerating his delusions. And Waner pointed out that Apostle's examination took place a year after the killing, implying he had time to embellish a story.

The trial has drawn the attention of mental health advocates. Family members have said they want treatment for Herczog, not punishment.

Judge Dana Simonds on Thursday issued a warning to a Herczog relative who demonstrated outside the courtroom door by holding up a magazine cover story on mental illness. Marilyn Herczog was arrested at a pre-trial hearing in late March for displaying a picture of her son and late ex-husband.

Both sides are expected to make closing arguments Friday.

A guilty verdict would lead to a second phase of the trial to determine Herczog's sanity.

Herczog could be sent to a mental hospital if he is found to have been suffering a mental break or be sentenced to 25 years to life in prison if he is determined to have been sane.