California Code, Penal Code - PEN § 136.1

(1) Knowingly and maliciously prevents or dissuades a witness or victim from attending or giving testimony at a trial, proceeding, or inquiry authorized by law.

(2) Knowingly and maliciously attempts to prevent or dissuade a witness or victim from attending or giving testimony at a trial, proceeding, or inquiry authorized by law.

(3) For purposes of this section, evidence that the defendant was a family member who interceded in an effort to protect the witness or victim shall create a presumption that the act was without malice.

(1) Making a report of that victimization to a peace officer, a state or local law enforcement officer, a probation, parole, or correctional officer, a prosecuting agency, or a judge.

(2) Causing a complaint, indictment, information, or probation or parole violation to be sought and prosecuted, or assisting in the prosecution thereof.

(3) Arresting or causing or seeking the arrest of a person in connection with that victimization.

(1) If the act is accompanied by force or by an express or implied threat of force or violence, upon a witness, victim, or any third person or the property of a victim, witness, or any third person.

(2) If the act is in furtherance of a conspiracy.

(3) If the act is committed by a person who has been convicted of a violation of this section, a predecessor law, a federal statute, or a statute of any other state that, if the act prosecuted was committed in this state, would be a violation of this section.

(4) If the act is committed by a person for pecuniary gain or for any other consideration acting upon the request of any other person.  All parties to the transaction are guilty of a felony.