I carry based on a best reasonable guess as to what I may be dealing with. I'm not on the job anymore so a J Frame + 5rd strip, Glock 26 with no extra mag or Model 65 + 6rd strip is usually it.

That said, were I day-to-day working directly with people who don't play by societies rules, and simply not being there anymore wasn't a reasonable option, I'd probably be packing something more. People sometimes react badly when they think you may take away their freedom. Were I doing your job in today's climate, personally I'd be packing a smallish duty weapon like a Glock 19 or Colt Commander + a spare mag and a J frame. That's just me though - belt and suspenders.