I have a case where the defendant was found in possession of some 28 grams of hash oil. Under Penalty Group 2 (Tetrahydrocannabinols), is not illegal to possess if the person has a valid prescription (CSA 481.116). Defense counsel is arguing that defendant's prescription for medical marihuana is valid under this exception. My stance is that a marihuana prescription, from a State where marihuana is legal, is not valid in the State of Texas. Has anyone else come up across this argument from defense attorney's? Has anyone run into defense attorneys who have had success with this argument?

Why would it be any less valid than an Rx for any other kind of medicine? How would such an argument play out in front of a jury?

I think your defense counsel is confusing the issue of marijuana and Tetrahydrocannabinols (THC). There is no prescription defense to possession of marijuana in CSA 481.121. See Bruyette v. State, 253 P.3d 512, 514-15 (Wyo. 2011) (out of state prescription for marijuana is no defense to marijuana prosecution and trial court properly granted in limine motions barring references to prescription).

There is such a defense for THC possession. If your guy had a prescription for Marinol (THC) he might be ok. But your guy didn't have a prescription for THC. See generally Aycock v. State, 246 S.E.2d 489, 494-96 (Ga.App. 1978) (discussing the difference between THC and marijuana). Your guy's position is akin to arguing that a prescription for opium poppies is a defense to morphine possession.

Your case is sort of like Stefanoff v. State, 78 S.W.3d 496, 503-04 (Tex.App. – Austin 2002, pet. ref'd) (marinol prescription did not prevent trial court from imposing probation condition that defendant stop using marijuana).

(1) What does "valid" mean? Does the prescription have to be valid under Texas law? (2) Can a practitioner in another State issue an order that allows conduct in another state, or just where he practices? (3) Would the drug's use "permit" be considered to have arisen in the course of professional practice when no such practice is recognized in Texas?

This ground of defense seems fraught with difficulties, especially in light of Wright v. State, 981 S.W.2d at 200, which states: "Section 481.002(39) defines "practitioner," in relevant part, as a Texas physician or a physician registered with the Federal Drug Enforcement Administration, so the third clause of § 481.117(a) does not authorize the possession of foreign-prescribed controlled substances.

A prescription in one state for a drug that is illegal in another does not have to be recognized by the other state. Analogize it to a Texas CHL (which does not permit concealed carry in states that don't authorize it) or same-sex marriage (which is not required to be recognized by all states or the federal government). This is precisely the kind of issue that the public policy exception to the full faith and credit clause addresses.

And out of curiosity, how can a prescription be "valid" under Texas law when it is illegal under federal law?

I recently went to a conference in Colorado where this issue was addressed. There are federal guidlines under which a Doctor can prescribe medication. If you look at those, then ask yourself can a Doctor meet those requirements with Marihuana, or the hash in your case, then you will find the answer is no. This is why Dr's only certify someone to be a candidate for Marihuana therapy, but they do not actually prescribe it to them.