A FOOTBALL steward usually trusted to help control crowds turned hooligan during the rioting that rocked the City of London last year, a court heard on Wednesday.

Former Watford Grammar School pupil and dedicated community worker Daniel Martindale regularly helps staff matches at Watford Football Club - but last summer joined a hardcore band of thugs causing mayhem in the Carnival Against Global Capitalism.

The 24-year-old was caught on camera attacking police near London Wall after the protest descended into violence, resulting in millions of pounds worth of damage, Southwark Crown Court heard.

Later, with his distinctive white T-shirt pulled over his head as a rudimentary disguise, Martindale was part of a mob that smashed its way into the London International Financial Futures Exchange (LIFFE) to wreak further havoc.

Martindale, whom the court heard had been caught up in a 'crown mentality', works as a volunteer for the West Watford Community Association in Harwoods Road, where, among other duties, he is a liaison officer between the football club and youngsters with disabilities wanting to attend matches.

The art student, tipped for a first class degree from Camberwell College of Art next year, was jailed for four months.

Judge George Bathurst-Norman told Martindale it was a 'lenient' penalty, but he was able to show mercy after reading how the defendant overcame dyslexia and memory problems to take a degree course, and was a dedicated community worker.

Martindale, currently of Peckham, south east London, admitted two charges of violent disorder on June 18 last year.

Sentencing, the judge said the offences were so serious that only a custodial term was justified.

He added: 'The message has to go out to make it clear to others on this kind of demonstration, about the danger they create in indulging in actions of this kind - not least because it encourages others to act in the same way.'

But the judge accepted Martindale had acted totally out of character, and in 'a great many ways' had made a very positive contribution to society. He said: 'I also bear in mind you have had to overcome dyslexia and had to work extremely hard to do that.'

The court heard that out of some 5,000 demonstrators at the event, only between 200 and 300 had resorted to violence.

The judge said: 'I would be the last person in the world to limit freedom of speech'. But he added the real 'evil' was such behaviour provoking others to violence, and making the task of policing demonstrations even more difficult.

He said it had been a terrifying experience for police officers in the vans when they were attacked, not knowing if the vehicles would be turned over, and helpless security guards at the LIFFE building were also 'terrified' by the mob.

The judge told Martindale, who also works for the Watford Reclamation Artistic Project, that the sentence would allow him to sit the final year of his degree.

Ms Mary Green, co-ordinator of the West Watford Community Association, this week confirmed that Martindale would be welcomed back as a volunteer after his prison spell ended.

She said: 'He is a very committed, caring and conscientious member of society. I know he has certain political views but we have always seen him as a responsible young man.'