Green’s Dictionary of Slang

the police.

1975		H. Ellison Deadly Streets (1983) 11: When the local bacon finally arrived, the guys had split.
1997–2000		Da Bomb 🌐 bacon (n) The police. This donut shop smells like bacon. Slow down, I smell bacon. [University of British Columbia, Vancouver, BC, Canada, 1998].
2002		‘Touré’ Portable Promised Land (ms.) 156: We Words (My Favorite Things) [...] Pig. 5-0. Bacon.
2012		(con. 1980s) I. Welsh Skagboys 71: Naebody loves ex-bacon.
2013		T. Black Ringer [ebook] n.p.: If it was the pigs they'd be battering down the door and make no mistake, tends to get a wee bit jumpy when there's Class-As concerned, does Mr Bacon.
2013		F. Bill Donnybrook [ebook] Alonzo said, ‘Nosy piece of bacon.’ A deafening blast erupted from the .30-30’s barrel. Half the officer’s face opened.