I wouldn't worry too much if a peace officer carried a reliable .380. Not my choice, either, but some guys can really shoot those Walthers. If I happened to be in a gunfight, and had to use my wife's German-made PP, I would not feel helpless; that thing is accurate. I think detectives with my agency can still choose to qual with a .380 as primary, though if they ever put on a uniform, they must follow the same rules as everyone else.
Until 1997, we could carry pretty much anything, .38/9mm up to .45, auto or DA sixgun. After 1997, we could keep carrying the earlier weapons, which were "grandfathered," but all new duty handguns after that time had to be certain specified .40 autoloaders, with the early list being a certain, now-obscure decock-only S&W model, the Beretta Cougar, and the SIG P229. The list is a bit larger now. I used grandfathered 1911s until 2002, but now am "with the program" by carrying P229s. We do still buy the weapons ourselves. The G22 is the single most popular duty pistol now, and my P229 marks me as as being either wealthy or a "gun guru," neither of which are really true.
Unusual duty handguns I carried before 1997 included HK P7, S&W M58 .41 magnum, Browning Hi-Power .40. Only the .41 was carried for very long, from 1985 into the early 1990's.
I have seen several Taurus clones of the Beretta 92 in other officer's rigs. Other unusual pistols included HK P9S, VP70Z, and P7M13, various Stars, one Grizzly .45 Winchester Magnum, S&W Sigmas, and quite a few Colt Delta Elites.
Through attrition, most duty pistols seen after day shift leaves for the day will be the currently specified .40 autos, though 1911s and BHPs have a large enough following that they can be seen any time. Many older officers who had originally grandfathered their heavier guns eventually bought .40 Glocks, which were added to the approved list in the early 2000's.