There were surprising revelations Tuesday in the Etan Patz murder trial, as a psychiatrist testified that the defendant is mentally ill, had a costly cocaine habit and beat his wife more than once because she wouldn't pay for his drugs. NY1's Michael Herzenberg filed the following report.

A judge ruled Tuesday that Pedro Hernandez's drug and domestic abuse are admissable, bombshell evidence that the accused murderer's defense team wanted to keep from jurors.

Pedro Hernandez had a $1- to $300 a week cocaine habit at times between 1985 and 2005. A couple of times, when his wife wouldn't pay for it, "things got violent."

The revelation came from a defense witness, forensic psychiatrist Dr. Michael First, who said the cocaine use was sufficient to cause psychotic symptoms. That could sow doubts in the minds of jurors about the defense's chief argument, that mental illness caused Hernandez to hallucinate that he killed Etan Patz.  

The psychiatrist testified that Hernandez suffers from a less severe form of schizophrenia called Schizotypal Personality Disorder. The psychiatrist said Hernandez told him a "voice told me to lure the child in."

Six-year-old Etan Patz vanished in 1979 on the way to his bus stop and the SoHo bodega where Hernandez worked.

First said there is evidence that the defendant had hallicinations even before he began abusing cocaine, and that he has trouble distinguishing fantasy from reality.

"He's completely unclear as to what's real and what's not," First said.

On cross-examination, though, the prosecution tried to frame Hernandez as a liar, pointing out that his stories grew more outlandish as he spent more time behind bars, perhaps in an effort to convince people he is crazy.

Initially, before he was held in jail, he told the psychiatrist, "I know I did it." But by his third examination, after two months on Rikers Island, he claimed 15 people - some in white gowns - watched him strangle a child.

The prosecution will continue cross-examining First Thursday morning.