The case never made the headlines, or even local news reports, but it made a big difference to 21-year-old James Hooper. Last year Hooper was convicted at Reading Crown Court of handling stolen cars. To have a criminal record at his age is not helpful; but the conviction was especially galling, since it was for something he hadn't done.

"At the start of the trial my barrister said to me, 'This will be no problem at all'," Hooper recalls. "Halfway through she suddenly said 'It's not looking so good now'. At the end my legal team were saying 'What bad luck'."

Richard Boult, a retired RAF squadron leader, had known the Hooper family for some years. "I knew James as a completely honest young man," he says. "When he asked if he could set up a small garage in my carport, I agreed immediately."

Hooper took in cars that had been wrecked or had suffered engine failure and broke them down to sell as parts. "I'd arrange for a mechanic to take an engine out, or someone to strip a car down. I was just being a small businessman; it was something I enjoyed," he says.

Peter Smith (not his real name), a friend of a friend, asked to become involved. Hooper agreed and paid him wages. Smith brought in cars that, unknown to Hooper, were stolen. He and Smith were arrested and put on trial. Both were convicted but Hooper, as the alleged ringleader, received the stiffer sentence (100 hours' community service).

However insignificant, the case raises several issues about the criminal justice system. First, Smith was imprisoned on a separate matter after he and Hooper were arrested. Police visited him in prison and it was then that he changed his story to make out that Hooper had been behind the operation. Yet, when Smith gave his damaging evidence, ascribing a lesser role to himself and a major one to Hooper, the jury had no idea that he had a string of convictions for theft and was an experienced defendant. Had they known, they would almost certainly have assessed the case differently.

The second issue concerns the use of video recordings in court. Police had put Boult's house under surveillance. For 32 days, 24 hours a day, activities at the carport were monitored and recorded. All this videotape was edited down to four tapes, then to one. Finally, in court, the material was cut still further by the judge, who manipulated the "play" and "fast forward" controls.

Out of all the video surveillance, there was one vivid image, replayed in court, showing Hooper throwing a tarpaulin over a car. The car had no window glass in it at the time and Hooper wanted to keep it dry; but, taken out of context as it was, the image looked suspicious.

The problem with videotapes in court is that they are filleted and edited to suit a particular perspective. The 99.9 per cent of the tape that could throw a different light on the case is never seen by the jury.

The third issue is difficulties with legal representation. "On the last day of the trial, when the judge was to finish summing up and send out the jury," recalls Boult, "James's barrister wasn't in court." She sent somebody else. "No doubt she had pressing business elsewhere but what message is that sending to a jury?" The fourth issue is the capacity of the criminal justice system to make mountains out of molehills. This case took 18 months to prepare and the trial lasted two-and-a-half weeks. Yet Hooper never made more than a few hundred pounds from the business.

Recognising that a criminal conviction could be a serious impediment to a future career, Hooper is determined to get it quashed, and has submitted his case to the Criminal Cases Review Commission. "It sticks in my throat to see this injustice, which could trip James up years in the future," says Boult.