A prosecution psychiatrist who deemed a 22-year-old Santa Rosa man sane at the time he stabbed his father at least 60 times, killing him, came under fire Tuesday about his administration of personality tests and alleged missteps in preparing his report.

It was the second day of cross-examination for Dr. James Missett, the only psychiatrist among four to deviate from a diagnosis of paranoid schizophrenia for Houston Herczog.

Herczog's attorney, Karen Silver, hammered Missett about answers on a true-or-false test given to Herczog in jail that appeared to be done in both pencil and pen.

Missett stumbled when asked to explain the use of two different writing implements. And he admitted that he transcribed Herczog's responses to an answer sheet, filling in the bubbles himself, which Silver described as a violation of testing protocol.

Pressed on the issue of pencil and ink marks on the testing forms, Missett said that Herczog left dozens of questions unanswered and went back at the doctor's urging to complete them, possibly using a pen.

"He put T or F next to the statement," Missett said. "As he did, I would fill in the bubble sheet."

But his uncertainty about what happened was apparent. Missett testified several times that he simply could not remember parts of the test, administered in late March.

And he wasn't able to say how he obtained another doctor's report, which he mistakenly faxed to the District Attorney's Office along with his own findings.

Herczog's lawyer insisted the errors and confusion invalidated Missett's finding that Herczog killed his father during a drug-induced rage, and not because he was suffering mental illness.

"It's my argument that those are not Houston's answers," Silver told Judge Dana Simonds late Monday. "And it is certainly not reliable."

Herczog has pleaded not guilty by reason of insanity in the November 2011 slaying of his father, Mark Herczog, 63. The elder man was stabbed to death in the kitchen of their Rincon Valley home after father and son had a late-night confrontation.

Herczog was convicted earlier this month of first-degree murder. Now, the same jury panel is listening to testimony to decide his mental state at the time of the killing.

If he is deemed sane, he could be sentenced to life in prison. An insanity finding would put him in a mental hospital instead.

Three doctors who examined Herczog concluded the killing happened during a psychotic break. They found Herczog was suffering delusions and hallucinations that his father was possessed by an evil force and had to be killed.

Psychiatrist Robbin Broadman testified Monday that it was the deadly climax to about two years of declining mental health. "His pattern of deterioration ... is so classic," Broadman said.

Prosecutors hired Missett on the eve of trial at a rate of $300 to $400 per hour. He determined that Herczog killed his father in a rage brought on in part by the use of his mother's prescribed stimulant, Adderall.

Missett also concluded based on Herczog's statements to police that he might be exaggerating any mental condition.

He portrayed Herczog as a "very intelligent" person who was capable of deception to avoid prison. Testing found a high probability that he is malingering, Missett said.

"It was a rage attack," Missett said Monday. "It was nothing more than a person who became very angry."