Mr Johnson rebels

Mr Johnson sits on the train home and reads his paper. "Young father stabbed to death by youths reads the headline. Mr Johnson does not blink.

Over the loudspeaker comes the announcement: "Yo bloods, you gotta smoke the marijuana. Kids, at the front of the carriage, messing about with the intercom system. The other passengers lower their eyes. Mr Johnson reads on, trying not to be distracted.

"So he stabbed her right in the chest and no one could touch him 'cos he was only thirteen, swear down.

The kids, three of them, walk ahead of Mr Johnson, all wearing baseball caps the wrong way. They have alighted at his station. Mr Johnson is surprised. He lives in a nice area. It is after eleven o'clock, and not one of them looks over fourteen years old. How curious, he thinks.

One night he retrieves an illegal butterfly knife from his childhood collection. He never thought, back when he was younger, his fascination with knives was strange, he simply liked the look of them.

"And you say you feel no remorse?

"No, sir.

A child turns up to one of his lessons with blood-shot eyes one morning, complaining she can't write because her head hurts. "I'm so hungover, she complains, "I was out til two last night.

Mr Johnson recalls Newsround, The Flinstones, Coronation Street, and how soft his sofa and bed felt. Mr Johnson is thirty-two.

"Was there any provocation? asks the prosecutor.

Mr Johnson thinks carefully about this one. "No sir. I suppose not, he replies, finally.