Prosecutors Say Gerson's Insane -- Judge To Rule On Arsonist's Plea

King County prosecutors have agreed that Marc Gerson was legally insane when he set fire to his family's Redmond home in January, killing his sister and her 9-year-old son.

Now it's up to a King County Superior Court judge to decide Monday whether to either accept Gerson's insanity plea and send him to a mental hospital or refuse the plea, triggering a jury trial and the possibility of life in prison.

"I think they listened, and the prosecutors took their time and were very careful and made the correct decision," Gerson's mother, Ellen, said yesterday. "I do think he will get treatment and good treatment."

Gerson, 31, is charged with two counts of first-degree murder and one count of first-degree arson.

On Jan. 22, prosecutors say, Gerson piled blankets outside family members' bedroom doors, doused them with gasoline and set them ablaze. His sister, Jennifer Gerson, 35, and her son, Richard, died in the fire. Marc Gerson's father, Philip, spent six weeks in the hospital with burns over his arms, hands and legs. His mother escaped with slight injuries.

Gerson, who has suffered from mental illness since he was 19, said he heard demons tell him to burn down the house.

Gerson's lawyers asked to plead insanity. By agreeing that Gerson was insane, King County prosecutors leave the details of his sentencing to Superior Court Judge William Downing, spokesman Dan Donohoe said yesterday.

If Gerson's attorneys and prosecutors had not agreed to the

plea, the case would have proceeded to a jury trial. Gerson's lawyers still could have tried to convince a jury of his insanity.

Although both sides concur on the insanity defense, Downing still needs to approve it. The judge could override the arrangement and order a trial.

If the judge accepts the agreement, Gerson would be sent to Western State Hospital in Steilacoom, Pierce County, as a psychiatric patient under the care of the state Department of Social and Health Services. Although Gerson would be supervised for the rest of his life, he could leave Western State if doctors and a judge approve his release.

"His symptoms can be controlled if he takes the proper medication, and takes it religiously," his mother said. "He feels that incarceration would not be the appropriate thing, and that he has to accept that he belongs in a system for mentally ill people."

Prosecutors declined to comment on their decision until the hearing Monday. But key elements leading to the plea were Gerson's long battle with mental illness and the chain of events that led to the fatal fire.

A graduate of Mercer Island High School, Gerson was first hospitalized for mental illness during his freshman year at The Colorado College in 1985. He was later diagnosed with schizo-affective disorder, which includes characteristics of schizophrenia and bipolar disorder.

Since then, he has been hospitalized more than 20 times, including stays at Harborview Medical Center and Providence Seattle Medical Center in Seattle and Fairfax Psychiatric Hospital in Kirkland.

Gerson was discharged from a five-day stay at Overlake Hospital Medical Center in Bellevue a day before he set the fire that killed his sister and nephew. He had been released to stay with his parents in Redmond.

After his arrest, Gerson was sent to Western State Hospital for an evaluation to determine whether he was competent to stand trial.

Two mental-health professionals determined that Gerson understood what he had done and could follow the court process. The report said Gerson was competent to stand trial if he continued to take antipsychotic and mood-stabilizing medications.

The evaluation also stated that Gerson suffered from chronic psychotic illness: "Specifically, he believes that there is a struggle between God and the Devil for his soul and that he must perform certain acts to prevent his soul from `going to hell.' "

The report said that Gerson has a history of impulsive violence and "would be an extreme risk for future violence" if he discontinued anti-psychotic medications.

Seattle Times staff reporter Eric Sorensen contributed to this report.

Alex Fryer's phone message number is 206-464-8124. His e-mail address is afryer@seattletimes.com

Ian Ith's phone message number is 206-464-2109. His e-mail address is iith@seattletimes.com