A THUG who kicked a paedophile to death was last night revealed to be a convicted sex offender himself.

Adrian Brown broke into the rundown home of 73-year-old Arnold Hartley and stamped on his head repeatedly before throttling him in a drink-fuelled attack.

The 42-year-old, from Redcar, in Cleveland, later laughed about the attack, boasting to friends that all child molesters should be "put down".

But behind the sadistic boasts, Brown had a guilty secret of his own.

Newcastle Crown Court heard how the killer had a string of convictions for crimes stretching back three decades - including one for a sex assault on a teenage girl.

A jury of sex men and six women took under four hours to convict the 42-year-old, of Redcar, Cleveland, of murder.

The heavily tattooed Brown, who denied murder, stood expressionless in the dock as the jury foreman returned the unanimous verdict.

Jailing Brown for life, with a recommendation he serve at least 14 years, Mr Justice Fulford said: ''The seriousness of what you did is not in any way lessened by the sordid way of life the person you killed led.

''The fact he was a convicted paedophile who preyed on young teenage girls does not begin to give you any justification for assaulting and killing him.''

The sentence was handed down on the day the Government released figures that showed there are 1,637 registered sex offenders living in the North-East and North Yorkshire.

Brown's victim Arnold Hartley was jailed in October 2001 after being convicted of a series of sex attacks on teenage girls.

After his release from prison, he returned to his home in Queen Street, Redcar, and was subjected to a vigilante hate campaign, which included bricks put threw his windows.

Brown broke into his home during the early hours of November 29, 2003, after drinking heavily the previous evening.

He punched the pensioner in the face several times then repeatedly stamped on his face and neck before strangling him.

Even as a friend tried to drag the defendant away, he continued to stamp on the pensioner's head, shouting: ''He deserved it. He's a paedophile. He deserves everything he gets.''

Brown, who was accompanied by Thomas Croft, 42, and a 16-year-old girl, then rifled through the old man's pockets and stole some money before fleeing.

A few days after the murder, Brown laughed about what he had done and boasted to a friend: ''All paedophiles should suffer the same. They all deserve it, they want putting down.''

Defence barrister Aidan Marron said: ''This was not a planned offence, not premeditated. It seems to be the work of the moment, the product of a spontaneous explosion.''

The court was told how Brown was convicted at Grimsby Crown Court of the indecent assault of a girl under the age of 14 and sent to Borstal when he was 16 years old.

He was later jailed for three-and-a-half years at York Crown Court in 1995 for slashing a shopkeeper with a knife.

Cleveland Police said: "Arnold Hartley was a convicted sex offender and some people like Adrian Brown thought that gave them the right to subject him to abuse and attack. Mr Hartley was a sad old man, whose latter life was made a misery.''

"Adrian Brown is a thug and a bully. He thought he could attack Mr Hartley with impunity and the public would turn a blind eye to his crime. He was wrong."

Police last night attempted to calm fears over Home Office figures which showed a continued rise in registered sex offenders living in local communities.

Northumbria recorded the largest rise from 632 to 750 as at March 31 this year.

Figures for County Durham showed a rise from 240 to 265 between 2002 and 2003; Cleveland from 303 to 339 and North Yorkshire from 234 to 283.

Police and probation officials said the rise was due to new offenders being detected and required to register as sex offenders under Government legislation.

The figures were released as part of a series of reports on so-called Multi-Agency Public Protection Arrangements (Mappa) which bring together police, probation, social services and other agencies to monitor violent and sex offenders in the community once they are released from jail.

The Mappa report for County Durham warned of individuals taking the law into their own hands and cited the case of one newly released prisoner who was attacked and threatened.

The report said: "We would want to reinforce that if an offender has to be moved suddenly due to local threats, the risk of them repeating their offending increases."