Defense lawyers argue that Francis Wolke, found guilty of first-degree murder last week in the 2018 killing of Atherton arborist Kathy Hughes Anderson, was insane and believed he had to commit cannibalism in order to join the "1%" and stay young forever.

The claim arose during court proceedings to determine whether Wolke was sane during the 2018 incident, following a guilty verdict by a jury on March 2. The sanity phase of the trial began Monday and is expected to conclude Tuesday, March 8.

Defense attorney Connie O'Brien argued in opening statements that Wolke was suffering from psychosis at the time of the murder and that he was unable to understand his behavior as morally wrong. According to O'Brien, Wolke believed "he had to murder someone and potentially consume parts of the body to become a 'protein harvester' and join the 1%."

Wolke believed that if he moved to California from Cincinnati, where he grew up, he would become incredibly rich and told his family that he had connections to important people in California. The "1%" Wolke was intent on joining refers to the incredibly rich and elite, whom Wolke believed would protect him because they were also committing acts of murder and cannibalism.

In the first phase of the trial, O'Brien said that Wolke had auditory hallucinations several times on the bus ride from Cincinnati to the Bay Area telling him that he had to commit sins to join the 1%, ultimately resulting in Wolke murdering Hughes Anderson with this intent.

Dr. David Berke, a forensic psychologist who testified, said that Wolke believed "there exists a 1% of the population that kills people and eats their stem cells which gives them almost eternal youth," and that "what he did would be approved of by the 1%."

Berke also testified that Wolke, by staying in Hughes Anderson's house for hours following the murder and even taking a nap, proved he did not fully understand the gravity of his actions.

Wolke was tested and was not believed to be on drugs at the time of the murder despite heavy methamphetamine use in the past, but had shown evidence of psychosis without drugs in two prior hospitalizations for mental health.