Can you be arrested for swearing at an off duty policeman?

faults commited against a law enforcement officer is taken very seriously in a court of law. This does not mean they will allways win. So you might make your case in court but I highly do not recomend you go with the freedom of speech in mind causing offduty police officers to waste their precious off duty time on you.

Note that the prosecution success rate for lude speech towards a law enforcement officer in the year 2008 was .02%