The prosecution must prove four facts to prove that you are guilty of drug possession. • You possessed the drug. • You knew you possessed the drug. • You knew what you had was a controlled substance; and • There was enough of the drug to be used as a drug—they cannot prosecute you on the basis of useless traces or drug residue.  This does not mean that your drug case will be straightforward. It is important to discuss these four points with an experienced drug attorney. If the prosecution cannot prove any of these four points then that might lead to a defense for your drug case. This could mean the DA drops the drug charges, or it can mean beating your drug case at trial.