California Code, Penal Code - PEN § 1367

(a) A person shall not be tried or adjudged to punishment or have their probation, mandatory supervision, postrelease community supervision, or parole revoked while that person is mentally incompetent. A defendant is mentally incompetent for purposes of this chapter if, as a result of a mental health disorder or developmental disability, the defendant is unable to understand the nature of the criminal proceedings or to assist counsel in the conduct of a defense in a rational manner.

(b) Section 1370applies to a person who is charged with a felony or alleged to have violated the terms of probation for a felony or mandatory supervision and is incompetent as a result of a mental health disorder.Section 1370.01applies to a person who is charged with a misdemeanor or misdemeanors only, or a violation of formal or informal probation for a misdemeanor, and the judge finds reason to believe that the defendant has a mental health disorder, and may, as a result of the mental health disorder, be incompetent to stand trial.Section 1370.1applies to a person who is incompetent as a result of a developmental disability and applies to a person who is incompetent as a result of a mental health disorder, but also has a developmental disability.Section 1370.02applies to a person alleged to have violated the terms of the person's postrelease community supervision or parole.