Louisiana Code of Evidence Art. 507. Subpoena of lawyer or his representative in criminal cases

A. General rule. Neither a subpoena nor a court order shall be issued to a lawyer or his representative to appear or testify in any criminal investigation or proceeding where the purpose of the subpoena or order is to ask the lawyer or his representative to reveal information about a client or former client obtained in the course of representing the client unless the court after a contradictory hearing has determined that the information sought is not protected from disclosure by any applicable privilege or work product rule; and all of the following:

B. Waiver. Failure to object timely to non-compliance with the terms of this Article constitutes a waiver of the procedural protections of this Article, but does not constitute a waiver of any privilege.

C. Binding effect of determination; notice to client. The determination that a lawyer-client privilege is not applicable to the testimony shall not bind the client or former client unless the client or former client was given notice of the time, place, and substance of the hearing and had an opportunity fully to participate in that hearing.

D. Exceptions. This Article shall not apply in habitual offender proceedings when a lawyer is called as a witness for purposes of identification of his client or former client, or in post-conviction proceedings when a lawyer is called as a witness on the issue of ineffective assistance of the lawyer.

E. The procedural provisions and protections afforded by Paragraph A of this Article shall extend to lawyers serving as prosecutors in state, parish, or municipal courts, whether those functions are exercised in the name of the state of Louisiana or any parish or municipality, and whether the lawyer is the attorney general or assistant attorney general, a district attorney or assistant district attorney, or a parish or municipal prosecutor, and shall extend to lawyers employed by either house of the Louisiana Legislature.