The police just can't be bothered to take on this sort of crime anymore. Not due to the officers laziness, simply because it's not worth it. If they'd have arrested them, it would have been hours of paperwork, then in several months it would have gone to the Magistrates Court (who are the most useless body I've ever seen) who would have given them a non-sentence. Costing the taxpayer thousands of pounds for no actual result. Is it any wonder morale is low within the police and they're reluctant to take action?
I know of someone who got shot at this week, but as the bullet didn't hit the person, the police said there was no point in taking it further!