An offense
Late one Friday night the policeman spotted a man driving very erratically through the streets of Dublin. They pulled the man over and asked him if he had been drinking that evening."Aye, so I have. 'Tis Friday, you know, so me and the lads stopped by the pub where I had six or seven pints. And then there was something called "Happy Hour" and they served these mar-gar-itos which are quite good. I had four or five o' those. Then I had to drive me friend Mike home and O' course I had to go in for a couple of Guiness - couldn't be rude, ye know. Then I stopped on the way home to get another bottle for later .." And the man fumbled around in his coat until he located his bottle of whiskey, which he held up for inspection.The officer sighed, and said, "Sir, I'm afraid I'll need you to step out of the car and take a breathalyzer test."Indignantly, the man said, "Why? Don't ye believe me?!?"

A staged wedding to bust dealers
As supposedly reported on CNN:

Undercover police, staging the wedding of "a drug kingpin's daughter", let it be known on the street that dealers were "invited" (i. e. Expected to attend).

The bride and groom were police, as was the band, bartender, and about half the guests. The band playing at the wedding was "S. P. O. C." (COPS, backwards), and the wedding went through the full ceremony, including the dancing afterward.

The long-sought dealers were arrested after the "band" took their break. The last song the band played before taking its break? "I Fought The Law, And The Law Won"