Voice of Charlie Brown pleads guilty to threats, blames mental health

Peter Robbins, the original voice of Peanuts character Charlie Brown, signs autographs at Comic Con in San Diego, July 25, 2008.

AP/Lisa Rose

Last Updated Nov 12, 2015 1:13 PM EST

SAN DIEGO -- A former child actor who was the voice of Charlie Brown in beloved "Peanuts" TV specials has pleaded guilty to making criminal threats.

Fifty-nine-year-old Peter Robbins of Oceanside, California, entered pleas Tuesday. He's facing four years and eight months in prison.

Authorities say Robbins threatened to harm a mobile home park manager and San Diego County Sheriff Bill Gore, offering $50,000 to have Gore killed. Robbins said the threats stem from his bipolar disorder and paranoid schizophrenia.

Two years ago, Robbins pleaded guilty to threatening a former girlfriend and her plastic surgeon.

From age 9 to 13, Robbins was the voice of Charlie Brown in a series of 1960s animated classics, including "A Charlie Brown Christmas" and "It's the Great Pumpkin, Charlie Brown."