Testimony in the murder trial of a former west Sonoma County man accused of killing his sister's boyfriend called into question his sanity Tuesday and pointed to a possible defense strategy.

Barbara Evans told jurors that her son, defendant Jarrod Miller, 30, reported seeing "green aliens" as a teenager living at home more than 10 years ago and woke up with a knife in his hands.

Not long after, he fell into deep depression when a favorite uncle committed suicide and he injured two friends in a drunken-driving crash, his mother testified.

She said she requested that doctors put him under psychiatric observation but he was rejected.

"For four months, he sat in his bedroom wrapped in a blanket," Evans testified of his reaction to his uncle's death. "He wouldn't talk to anyone."

Testimony followed from a forensic psychologist hired by Miller's lawyers who said he examined Miller and concluded he suffered from paranoid schizophrenia.

Thomas Cushing said Miller's score on a clinical test put him on par with those who believe they are "receiving messages" from electronic equipment such as radios and TVs.

"His score was consistent with people who experience hallucinations and delusions," Cushing testified.

The statements, which appeared aimed at a mental impairment claim, came during the fifth day of testimony in Miller's trial.

The ex-Marine and former El Molino High School student is accused of killing Timothy Neuer, 29, at his Alexander Valley home on March 8.

He faces two 25-years-to-life prison sentences if convicted of first-degree murder and a weapons charge. Conviction of a lesser degree could shave years off his sentence.

Prosecutors said in opening statements that Miller shot Neuer to death after the man and Miller's sister, Mandy Miller, confronted the defendant about mooching off them.

The couple allowed Miller to live with them briefly but kicked him out after becoming frustrated with his dependency.

District Attorney Jill Ravitch, who is lead trial prosecutor, called the killing a "planned execution." She said Miller bought a gun in Nevada and drove to Neuer's house, where he shot him three times in his living room.

She rested her case last week after calling numerous witnesses, including Miller's sister. Defense attorney Joe Bisbigilia picked up Tuesday, calling first Evans and then Cushing.

Jurors are expected to begin deliberations as soon as Friday.

On Tuesday, Ravitch cross-examined Miller's mother about her son's mental state, drawing possible alternative explanations for his behavior and attempting to illustrate his intellect.

In emotional testimony, Evans described a troubled upbringing in which Miller left high school and later went AWOL from the Marines.

About the same time his uncle died, Miller was confined to the house for four months as part of the terms of his drunken-driving conviction, Evans said.

And she discussed a jailhouse letter from Miller in which he requested books on topics such as quantum physics and talked about pursuing an engineering degree. The letter said he was reading 70-80 pages a day.

"You love your son very much, don't you Mrs. Evans?" Ravitch asked.

"I do," Evans responded, breaking down in tears.