my 2 cents.
i dont not at all consider this inappropriate behavior, i do consider this very unprofessional, and unbecoming of a police officer.
this is better then them sitting there cursing out the parade and every one in it, i live on the parade route literally, and i was chatting with some of the cops and they were not happy to say the least about being there also a good number of these guys are rookies and scared crapless so the figured join the fun and show every one hey we are humans vrs getting shot like the cops in the 90 2 of which did get shot also they are new to the street so its ok for them to make a rookie mistake we have all made one. one last thing u cant blame them that much they were most likely forced to work that shift so they figured if we have to be here lets make the most of it
just my 2 cents