A former California state mental hospital director lured young boys with pizza and trips to a mountain cabin to sexually abuse them over a span of four decades, a prosecutor said Tuesday.

After a weeklong trial, jurors began deliberations on 35 counts of sex crimes against former Napa State Hospital director Claude Foulk.

Prosecutor Danette Gomez said during her closing argument that the 63-year-old administrator used his degrees and accolades as a shield to fend off allegations involving the horrific abuse.

The boys — now grown men — turned to alcohol and drugs, and struggled to form lasting relationships due to the crimes, she said.

"Look beyond that facade and what you're going to see is nothing but a wolf in sheep's clothing," Gomez said as Foulk watched with a blank expression.

Foulk, who is charged with molesting his adopted son over the course of a decade, has pleaded not guilty to the charges, which include lewd and lascivious acts on a child and sodomy by use of force.

Prosecutors said another 11 men have come forward to claim Foulk molested them as children as far back as 1965, but only the case of Foulk's son could be prosecuted because of the statute of limitations.

Foulk testified in his own defense and denied the allegations. He said his son had a history of lying and suggested the allegations stemmed partly from a family conflict.

After his arrest last year, Foulk was fired from his post at the hospital, which houses adults mostly judged mentally incompetent to stand trial or found not guilty by reason of insanity.

In his closing argument, defense attorney Richard Poland urged jurors to consider the lack of physical evidence presented in the case. He argued that just because people say something happened, doesn't mean it did, pointing to sightings of UFOs and the Loch Ness monster.

He also said Foulk's son, whose testimony is the heart of the case, has a history of lying.

"How, if you didn't do something, do you prove you didn't do it?" Poland asked jurors.

The investigation into Foulk was sparked when someone reported sexual abuse to police after learning Foulk was head of Napa State Hospital, prosecutors said.

Detectives found evidence that boys had been molested in Long Beach, where Foulk had lived, and in Rancho Murieta in Northern California.

During the trial, Foulk's son wept on the stand and characterized the defendant as a monster who abused him from the time he was 9 until he fled home at age 21.

Four other men, including one of Foulk's foster sons, also took the witness stand to recount allegations of abuse.

The Associated Press is not naming the witnesses because it has a policy not to identify alleged victims of sexual abuse.

Gomez said Foulk began targeting boys in his own family then moved to children in the foster care system. He was a foster parent to two boys and adopted two sons, authorities said.

Foulk worked as a nurse, obtained a master's in business administration and held previous state jobs before working at Napa State Hospital.

If convicted of all the counts, he could face up to 280 years in prison.