Defense of Drug Cases in Texas
In a drug-possession case, the State has to prove that you knowingly possessed-that you knowingly exercised care, custody, control, or management-over the drugs. That means that they have to prove that you did something with the drugs (or helped someone else do so) while knowing that they were drugs.
Five basic defenses apply in possession cases in Texas:
The State can't prove they were drugs.
The State can't prove you knew they were drugs..
The State can't prove you knew you exercised control over the drugs.
The State can't prove you knew they were exercising control over the drugs.
The State broke the law to get the evidence against me.
(1)–(4) are inferential rebuttal defenses: if the State doesn't prove each element of its case, you win. So, for example, if drugs are found in the car you are driving, the State has to prove not only that you were driving a car with drugs in it, but also that you knew they were there (4) and that you knew they were drugs (2).
(5) is a motion to suppress. If the State only found the drugs in your car because they'd violated the law-they had stopped you without reasonable suspicion, for example, or they had searched you without probable cause or consent-they don't get to use that evidence against you. And if the evidence that they can't use against you is the drugs from your car, they've got no case.
There is a sixth defense to a drug prosecution in Texas, though, which is "they used an informant, they have to disclose his identity, and they're not willing to do that.