I think all the cops should deny it "It wasn't me"
Then, call in the forensic lab! Expert Witness
"Well, Me Prosecutor, having examined PC Smiths underwear, I can definately say that he broke wind between, 10.00am, and 11.00am"
Defense Lawyer (cross-examining)
"But can you say with certainty, that this fart was the one in question?"
There's definitely a script for a sketch here somewhere. Come back Monty Python, all is forgiven!