Imagine me 45 years ago - a young schoolteacher coping with an unruly class of 10-year-olds in the shadow of Leeds jail. When alarm bells rang they thronged the windows to see if anyone's dad was making a break for freedom. (Quite a few families had moved from slum to slum in order to stay near dad.)

One day, a lovable urchin called Stephen turned up late because the police had been questioning him at the derelict warehouse where he lived with his mum. During the night he'd stolen dog biscuits from a neighbouring warehouse to keep them fed for a couple of days. (He said you could make nice 'porage' just by adding cold water.)

To get at the biscuits he'd picked a padlock. He said he could easily unpick the locks on the drawers of my table and he proved it in front of his marvelling classmates.