Peter Robbins, 59, who was just nine when he first played Charlie Brown in the mid-1960s, faces four years and eight months behind bars when he is sentenced next month (07Dec15) for plotting to kill Sheriff Bill Gore.

In court in San Diego, California on Tuesday (10Nov15), the former child star told Superior Court Judge William Chidsey, Jr. he is "mentally ill" and has been diagnosed with bipolar disorder and paranoid schizophrenia.

In 2013, Robbins pleaded guilty to charges of threatening a former girlfriend and the surgeon who performed her breast augmentation. He was handed probation but served jail time for violations, including drinking alcohol and cutting off his tracking ankle bracelet.

Robbins, who hosted a radio talk show in Palm Springs, California, also appeared in the TV shows My Three Sons and Rawhide.