Credit: John Gibbins/AP

A former child actor who once voiced Charlie Brown in the classic animated Peanuts TV specials pleaded guilty Tuesday to threatening a mobile home park manager and attempting to hire a hit man to kill a San Diego Sheriff, multiple outlets report.

Peter Robbins, who faces up to four years and eight months in state prison, told San Diego Superior Court Judge William Chidsey Jr. that he suffered from bipolar disorder and paranoid schizophrenia.

“I’m mentally ill,” he said, according to the Los Angeles Times. “I’ve committed no crime.”

In 2013, Robbins received probation after he pleaded guilty to threatening both his girlfriend and the plastic surgeon who allegedly performed a breast augmentation on her. But he violated his probation by failing to complete a domestic violence class, cutting off his GPS monitoring device and drinking alcohol, and served four months in jail, the Times reports.

At the time of his arrest, he was living in Oceanside with his dog, Snoopy, the Times reports.

Robbins was just nine years old in 1965 when he became the voice of Charlie Brown in many of the “Peanuts” television specials. He also appeared on several television shows, including “My Three Sons” and “Rawhide,” the Timesreports.

His sentencing hearing is scheduled for Dec. 7.