A guy decides he just can't get everything done that his life requires, so he goes to a geneticist and has a copy of himself made. The process was a success, except the original guy was a very reserved polite gentlemen, while his double was the most brash, foul-mouthed creature to hit the face of the Earth. To make matters worse, his doppelganger would be everywhere, cussing and swearing up a storm and getting the guy into trouble--church, work, friendships--they were all being destroyed as people wondered why the sudden change. So one day the guy is crossing the bridge on his way home from work with his mirror image right on his heels, regaling him with every expletive known to man, and the guy snaps. He turns around and pushes the nasty creature off the bridge, where it plunges to its death. So...can you guess what he was arrested for? Spoiler: Click here for answer Making an obscene clone fall.
You've got me on this. All I can think of is: He was arrested for making the "bridge on the river Kwai".
When I first heard this joke (a thousand years ago) it was a professor at Ohio State that had seats at the top row of the football stadium. I didn't have to peek to know the answer....