Peter Robbins, a former child actor who voiced Charlie Brown in three of the classic Peanuts TV specials, has been sentenced to prison for making criminal threats.

Robbins, 59, has faced a series of legal problems since January 2013, when he was arrested at the U.S.-Mexico border. Then, he pleaded guilty to charges of stalking a former girlfriend and her plastic surgeon.

In May 2013, he was sentenced to a year in jail, but was given credit for already spending 110 days behind bars. He was then ordered to go to rehab for the rest of his sentence and also received five years of probation. He violated his probation and was arrested again, reports USA Today.

But while he was in jail, Robbins could not avoid trouble. According to NBC San Diego, Robbins admitted to writing threatening letters to the manager of his former mobile home park. In one letter, he also offered $50,000 to have the San Diego County Sheriff murdered.

In November, Robbins pleaded guilty. He also told the judge that he is “mentally ill” and bipolar.

During Monday’s hearing, Robbins asked to have that plea withdrawn. But the judge declined his request and sentenced him to four years and eight months in jail.

Robbins voiced Charlie Brown for A Charlie Brown Christmas, It’s The Great Pumpkin, Charlie Brown and three other Peanuts specials.