Postscript:

I'd forgotten the best bit. While the police were trying to corral the local yoof, a pair of joggers appeared at the top of the road. Joggers, like cyclists, have a secret code to abide by when it comes to pavement etiquette: too quick for the pedestrian category, too slow or tiny to join the vehicles, your true home is the empty road or else the pavement when no-one is looking.

Unfortunately, everyone was looking. Lady-jogger decided that it was best to give the police incident a wide berth. She crossed to the other side of the road and ran elegantly by without fuss. Male jogger, on the other hand, ploughed straight on. He was all set to jog right through the fracas - knife, dogs, yoof, police - as if jogging on a higher plain. It was only the fact that a policeman put his arm out to stop him which made him change his route, and even then he tried to have a 'Hey, look here...' bit of argy-bargy with the obstacle in question.

I wish they'd let him run on a bit, then they'd be allowed to arrest him, no?