Am acquaintance of mine was driving home from his shift working at the local radio station. He had smoked a joint before he got into the car and had placed the left over (known as a 'roach' for those who are not in the know about 'stoner slang') into his ashtray. He was about to turn onto the road that he lived on when he was pulled for 'improper turn signaling' (It was North Carolina, and I maintain to this day that the cop was not from the state, because no local uses their turn signals in North Carolina) and the cop said that he 'smelled marijuana'. My friend let him search the car, whereupon he found the roach. The guy postured for a bit and then told my buddy, "Okay I am going to let you go... THIS TIME (the prerequisite saying require when a cop lets someone off)." He then held up the roach about three inches from my buddy's face and said, "But, I am going to keep this!"
My buddy smiled at him and said, "Thank you officer. And, you enjoy that!"
The cop did not find that funny for some reason... 
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