because criminals should be the least of your problems. The police will confiscate your cash even if there is no actual proof of it being involved in a crime.
http://www.newschannel5.com/story/18241221/man-loses-22000-in-new-policing-for-profit-case
http://www.newschannel5.com/story/18241221/man-loses-22000-in-new-policing-for-profit-case