ive gotten out of 3-4 marijuana charges b/c of the cops doing it wrong. I mean I didnt get any type of drug conviction. usually you have to get a lawyer and they will give you a lesser charge usually just a fine. i forget what the charge was that they gave me..
the one time specifically the cop saw ground up tree leaves on the floor of my car (it was fall). So he was outside of my car and was like "alright im searching now thats pot on your floor" then after he was in my car he found some... lol. he showed it to me and i told him "see i told you that shit wasnt no pot, tthose leaves were dark brown, that shits neon green" lol got out of it though, he was supposed to use one of those chemical test before searching my car.