BEVERLY — A Danvers man with a history of mental illness will spend the next three years on probation after being found guilty of shaking his young son, who was misbehaving.

Among the conditions that Peter Daniels, 39, will have to obey is that he take the medications his doctors have prescribed for the bipolar disorder that has led to at least five hospitalizations since 1991, Salem District Court Judge Robert Cornetta ruled.

Daniels, who took the stand in his own defense, insisted that he doesn't need medication, claiming that he is not mentally ill and that the allegations were false, made by his child's mother because she doesn't have a dishwasher, a clothes washer or a bigger apartment.

The 2-year-old boy had a bruise on his neck and red marks on his chest after the first of two reported incidents, in December 2007. He did not suffer any serious injury.

The boy's mother testified that the child was hitting Daniels when she asked him to stop.

She said Daniels put his hands around the boy's neck and shook him. The terrified woman grabbed the child and left the house.

Daniels, a contractor, insisted he had simply used a quick martial arts move to "stabilize" the boy after he began "teetering." He testified that the boy was startled when Daniels yelled at him.

He offered to demonstrate what he had done on prosecutor Jane Prince. Prince asked him to demonstrate on a doll.

Daniels was arrested and subsequently hospitalized. After his release from the hospital, he returned to living with the boy's mother in Beverly. But she testified that Daniels began acting in ways that troubled her, and she eventually asked him to move in with his mother in Danvers.

One afternoon in May 2008, Daniels showed up at their Thorndike Street apartment and began pacing back and forth outside. When his former girlfriend showed up, she said, Daniels tried to take the boy from his car seat and then raised his fist at her in a threatening manner.

When police showed up to arrest Daniels, he again raised his fist and told the officer "Bring it on," which led to a blast of pepper spray and a charge of resisting arrest.

Daniels insisted yesterday he didn't know that the patrolman, who was in uniform and driving a marked police car, was a police officer.

Defense lawyer David Gabriel pointed to the testimony of a doctor hired as an expert witness, who said he saw no evidence of bruises on the child's neck. But Prince, the prosecutor, pointed out that the medical records include a description of the bruise and noted that the photos taken by police at the hospital were photocopies of a Polaroid, not of good quality.

Gabriel also tried to challenge the mother's credibility, citing disparities in the length of time she said Daniels shook the boy.

"You saw a man up there in denial," Prince told the judge, referring to Daniels.

"I don't think there's any doubt Mr. Daniels has issues," the judge said during his sentencing.

Cornetta went along with a request by both Prince and the child's mother to impose a three-year probation on Daniels, with conditions that include mental health treatment and medication, anger management and parenting classes, and cooperation with the Department of Children and Families.