Louisiana Code of Civil Procedure Tit. I, Art. 2932. Burden of proof in action to annul

A. The plaintiff in an action to annul a probated testament has the burden of proving the invalidity thereof, unless the action was instituted within three months of the date the testament was probated. In the latter event, the defendants have the burden of proving the authenticity of the testament, and its compliance with all of the formal requirements of the law.

B. In an action to annul a notarial testament, a nuncupative testament by public act, or a statutory testament, however, the plaintiff always has the burden of proving the invalidity of the testament.