A person is capable of making a testament if, at the time of making the testament, he possessed that capacity under the law of the state in which he was domiciled either at that time or at the time of death.
If the testator was capable of making the testament under the law of both states, his will contained in the testament shall be held free of vices if it would be so held under the law of at least one of those states.
If the testator was capable of making the testament under the law of only one of the states specified in the first paragraph, his will contained in the testament shall be held free of vices only if it would be so held under the law of that state.
La. C.C. § 3529