Tyrone Cowan's defense team claims his poor mental health means he couldn't commit first degree murder.
As Action News reported last week, Cowan can be very talkative. But he has usually held his tongue in front of the jury.
Cowan's fate may depend on what goes on in his head. Many of his thoughts are on public display -- like when he loudly told his attorney Monday he's frustrated with the case, not long after he called the prosecutor a jerk.
But the most important information is more hidden. One doctor diagnosed the accused murderer with several mental health problems -- including bipolar disorder, psychotic disorder, anxiety disorder, and mild mental retardation.
Dr. Avak Howsepian says those issues would make it hard to premeditate and deliberate -- two key components of first degree murder.
"An individual's ability to plan something and carry out their plan in some kind of a coherent, structured sort of way is interfered with by this flood of experiences and activity and thoughts," Howsepian said.
But prosecutors say Cowan's mental health is not nearly that bad.
In almost six years since police say he killed a woman he was trying to rob, Cowan has been committed to the Atascadero State Mental Hospital four times. But at least one of those times, doctors said he was malingering -- faking symptoms to get a better outcome. And in his taped interview with police on the night of his arrest, he seemed to negotiate with officers -- offering more information for a better deal.
"That would show a cognitive ability to plan and think ahead, is that fair?" prosecutor Lynmarc Jenkins asked Dr. Howsepian.
"Yes," the defense psychiatrist admitted.
Cowan's courtroom outbursts have not been enough to elicit much reaction from the judge. But ABC30 legal analyst Tony Capozzi say prosecutors could use it against him in closing arguments.
Attorneys will make those arguments Tuesday morning.