Forensic crackdown on Naples' dog dirt

Piles of dog excrement on the pavement are one of the curses of urban life.

In many places there are efforts to combat it. Some local authorities put considerable pressure on owners to bag and bin it, and fine those that do not.

But a very different approach is being tried in the Italian city of Naples.

The authorities there are harnessing the full force of forensic science to track down offending dogs and their owners.

Alan Johnston joined the dog dirt detectives on the streets of Naples.