Agree w/ that except for the salary. Pretty sure cops that have been on the force for a bit are doing pretty well, particularly if they're making OT from time to time.
in DC:
http://mpdc.dc.gov/page/salary-and-benefits
Base $57,094/year + OT, plus a bunch of benefits. Top step (after 25 years) salary base is $92,914/year + OT and benefits.
This is roughly in line with the rest of the country, which averages to base ~$56k/yr.
This is all assuming the cop isn't doing some shady shit under the table, of course. Speaking from experience in the restaurant industry, it's extremely common for cops to get full or partial discounts to build a good relationship so when you need the cops to come handle crazy homeless people or whatever, they show up quickly. It wouldn't surprise me if this kind of cost-of-living benefit were extended by a variety of other businesses to cops as well.