A suburban housewife serving as her own attorney was convicted Friday of fatally stabbing her therapist husband, ending a circus-like trial in which she cross-examined two of her sons and discussed her psychic powers.

Susan Polk, 48, was convicted of second-degree murder in the October 2002 killing of Felix Polk, 70, at the couple's home in Orinda, about 15 miles east of San Francisco.

She faces a mandatory term of 15 years to life in prison when she is sentenced July 14 in Contra Costa County Superior Court.

Prosecutors had sought a first-degree murder conviction, arguing Polk plotted to kill her husband so she could get his multimillion-dollar estate. But Polk countered that her husband died after she fought back in self-defense following years of abuse. Polk was a 14-year-old when she began treatment with Felix Polk.

It took the jury four days to reach a verdict in the 14-week trial, which juror Kathy Sommese described as a struggle.

Jurors did not think the killing was premeditated, but they had a hard time believing Polk.

"We didn't think Susan was credible," said juror Lisa Christwell. Sommese added that Polk was "delusional."

While on the stand, Polk discussed secret government experiments, psychic powers and the Sept. 11, 2001, attacks, claiming she predicted the World Trade Center attacks but her husband prevented her from alerting authorities.

Scores of observers came to the courthouse in the San Francisco suburb to see Polk in action and hear sensational stories of illicit affairs, mind control and family dysfunction.

Polk was animated and often angry throughout the trial. She talked over the judge, insulted prosecutor Paul Sequeira and continually called for a mistrial.

In perhaps the trial's most memorable moment, Polk's son Adam called his mother "bonkers" and "cuckoo for Cocoa Puffs," on the witness stand, referring to the catch phrase used in advertisements for the breakfast cereal. The judge had to hold back laughter.

Polk testified that her husband attacked her with a kitchen knife that she seized and used to stab him in self-defense. A pathologist testifying for her said Felix Polk died of a heart attack not dozens of stab wounds.

Sequeira argued Susan Polk had no wounds that would indicate she was protecting herself in a violent struggle.

Sequeira urged jurors to disregard the strange testimony and instead focus on what happened the night Felix Polk was killed. He argued Susan Polk was a manipulative liar who turned on anyone who didn't agree with her version of reality.

"Susan had no right to take him from us," Adam Polk said after the verdict.