I am set to try an Agg. Asslt. case in which the defendant stabbed his son in the back in the presence of the defendant's wife and daughter. The defense is insanity caused by the medication the defendant was taking at the time: Xanax, Prozac, Paxill, Ambien.

HERE'S WHAT I NEED: an expert (pharmacist) to rebut this defense. Any ideas for an expert? Thank you in advance!

That's an impressive buffet. Is there a blood test showing that each of those chemicals or their metabolites were actually in the defendant's system at the time of the offense? Without active intoxication, I'd move in limine to exclude any mention of chemicals that were not directly affecting the behavior of the defendant at the time of the offense.

The prescription medications still in the bottle (and not in the defendant) have no relevance to the crime. The burden of relevance is on the party that chooses to introduce the evidence. Without foundation showing that the defendant took the listed medication at the time of the offense, the expert's testimony is pertinent.

I did an appeal recently where the defense had called a pharmacologist named, Dr. Michael Oglesby who is a professor of pharmacology at the University of North Texas Health Science. He seemed very credible to me just reading the record. I would guess that you're looking for somebody like him.

Intoxication is not a defense, and certainly not an insanity defense.

No expert should be permitted to testify that the drugs caused legal insanity, because it doesn't meet the definition. Insanity, legally, is based on a mental disease, not intoxication.

So, start with a motion in limine. Move to a jury charge that instructs the jury that intoxication is not a defense, and forget about the rebuttal expert.

Insanity caused by involuntary intoxication would be a defense. So would involuntary conduct caused by involuntary intoxication. See generally Garza v. State, 829 S.W.2d 291 (Tex.App. � Dallas 1992, pet. ref�d)
I've got no idea whether he can raise either one of those as a factual matter.
The fact that he had a prescription doesn't absolutely bar a claim of involuntary intoxication. Compare Nelson v. State, 149 S.W.3d 206, 210 (Tex.App. -- Fort Worth 2004, no pet.) with Mendenhall v. State, 15 S.W.3d 560, 565 (Tex.App. -- Waco 2000) aff'd on other grounds 77 S.W.3d 815 (Tex. Crim. App. 2002).