CA Penal Code Section 1331

Disobedience to a subpoena, or a refusal to be sworn or to testify as a witness, may be punished by the Court or magistrate as a contempt. A witness disobeying a subpoena issued on the part of the defendant, unless he show good cause for his nonattendance, is liable to the defendant in the sum of one hundred dollars, which may be recovered in a civil action.