The Simpsons S13 E22 Poppa's Got a Brand New Badge

"Just a product of society that's lost its good manners."

Homer starts a security company with Lenny and Carl after the police are ineffective during a blackout, and eventually Mayor Quimby decides to have them replace the police. Homer finds that he excels at the job, but then he runs afoul of mob boss Fat Tony, who threatens Homer with death unless he leaves town.