A PERVERT who targeted teenage girls on Facebook was today locked up indefinitely for the protection of the public.

Matthew Crouch, 22, will be freed from prison only when experts from the Parole Board consider he is no longer a danger.

Judge Howard Crowson branded bespectacled Crouch "a significant risk" and warned it might never be safe to release him.

The judge said the mere fact he takes part in a sex offenders' treatment course would not be enough to eliminate the risk.

Crouch targeted four young females - three of school age - and threatened some of them harm when they spurned his advances.

He later confessed to a probation worker that he wanted to have sexual relationships with each victim - despite their ages.

The Northern Echo reported yesterday how Crouch threatened to rape and kill some of the girls if they did not comply with his demands.

Judge Crowson adjourned the case so he could learn more about a Probation Service assessment of Crouch being "high risk".

The author said the risk would be reduced by him taking part in the treatment programme, but the judge doubted that.

Christine Egerton, mitigating, argued that Crouch should not be given a sentence of imprisonment for public protection.

Miss Egerton said he would welcome treatment, and that he was confident he could manage his behaviour if he had it.

She had earlier described Crouch as an "immature, isolated individual" with learning difficulties and problems with social skills.

Teesside Crown Court heard all of those targeted by Crouch late last year and early this year lived in his home town of Hartlepool.

Crouch, whose most recent address was at Lumley Court, Hebburn, in South Tyneside, admitted a number of charges.

The offences included sexual activity with a child, inciting a child to engage in sexual activity, harassment and threats to kill.

Detective Constable Gemma Aveyard, of Hartlepool CID, said after the case: "Those who target vulnerable young people via social networking sites will be pursued and, wherever possible, brought before the courts."