Crime victim David Asher turned DIY lawyer when police refused to take action against a teenage burglar.

And the computer programmer, who had never entered a courtroom before, was today celebrating his successful prosecution after almost two years of fighting for justice.

After sentencing the 16-year-old, a District Judge condemned the police for letting the teenager walk free in the first place.

In March 2001, dad-of-four Mr Asher, pictured, caught the youngster - who was then 14 - red-handed with two others inside a shed outside his home in Sable Crest, Bradford.

Calling himself into the witness box at Bradford Youth Court yesterday, Mr Asher told how he managed to detain the boy until police arrived, despite his accomplices hurling bricks in a bid to free him.

Afterwards, he told of the extraordinary sequence of events leading to the private prosecution.

Mr Asher said: "An officer came back later that night and said they were not charging him and had let him go.

"I said: 'Hold on, what's that about? If you are not going to do anything give me his details so I can do it for you'."

He spent several months asking the police to take action and, as they steadfastly refused, he asked for the boy's identity and vital documents relating to the case.

"At one point, an inspector told me that he could not give me the youth's particulars because of the Data Protection Act," said Mr Asher. But having read up on the act himself, Mr Asher pointed out this was untrue.

"Within ten minutes he rang back, apologised and sent them off."

Yesterday the 16-year-old, who cannot be named for legal reasons, denied burglary with intent to steal but was convicted after a trial.

He was given a conditional discharge and his parents ordered to pay £150 towards Mr Asher's legal costs. The remainder will come out of the public purse.

The boy's solicitor David Tyrer had claimed he was sheltering inside the shed from rain.

But District Judge Roy Anderson said the boy was lying and had gone to steal.

He said: "It is unfortunate in the extreme that the police, faced with the evidence of a story which was likely to be regarded as implausible, decided not to take action that night."

Mr Anderson said he understood they "might have been under pressure" but added: "It does seem that at the very least they should have asked the opinion of the Crown Prosecution Service before deciding definitively not to proceed with any charges."

After the case a Bradford police spokesman said they were now pursuing the two other youths involved and added: "We have to make a judgement on cases based upon the evidence available to us and to the prospect of a successful prosecution and that is what we did in this case."

During the six-hour hearing, Mr Asher called his partner Lynne Lightowler and three police officers as witnesses before cross-examining the defendant at length.

Afterwards he said: "If I went to a solicitor I simply couldn't have afforded it.

"Before putting the case together I had a look in a courtroom and found it all a bit confusing.

"It has taken 20 months of battling the system. This was my 15th court appearance."

He said his case was just "the tip of the iceberg" and added: "Other people would have let it go but I suppose I am just awkward.

"I have always had complete faith in the court system, there was never any doubting that. The police should have done a lot more, after all that's what we pay them for."

Commenting on the verdict he said: "I am just pleased that we got the right result. Justice has been done at last. I just hope it means that this boy will stay on the straight and narrow from now on."

He added: "But I wouldn't recommend anyone else to take this path - it has been an awful lot of hard work."