guy caught on camera throwing greyhound into sea

I saw a couple of p1keys repeatedly throwing a pit bull from a small bridge into the river, it looked terrified, i was going to say something, but was with my wife and two young children, but what can you do when you are trying to deal with people who are above the law, i called the police, who were not at all interested, when i said they were clearly  travellers..if i was in charge of this country, they'd be some fuc4 ing changes