A TEENAGER who groomed young boys before raping and abusing one and sexually assaulting a further three has been jailed for more than nine years.

Mark Smith was told by a judge that his crimes - committed when he was aged just 17 - had left his victims traumatised and their families devastated.

Smith abused them after watching similar acts on YouTube and searching the internet for "naked children", "kids in the bath" and "kids on X-Factor".

He admitted sexually assaulting three youngsters and was found guilty of raping and abusing another after a trial at Teesside Crown Court last month.

His barrister, Joanne Kidd, said the 18-year-old, from Darlington, has Tourette's syndrome, is immature and had more in common with young children.

Miss Kidd said he had never been aggressive or threatening, and added: "He didn't do anything above and beyond the commission of the offences to frighten."

She told the judge that the rape was "brief and not persisted with" and said Smith had shown "real remorse" in an interview with a probation officer.

Judge Crowson imposed a Sexual Offences Prevention Order which bans Smith from unsupervised contact with under-16s and restricts his computer use.

As well as being jailed for nine years and four months, he was put on the sex offenders' register for life and will banned from working with children.

Judge Crowson told Smith: "Although the rape was shortlived, the effect on [the boy] was very long-term, and it's not just him. It's his whole family.

"Although his mother thinks she is to blame for letting him down somehow, she should not think like that, as it's not her fault. It was yours."

In an impact statement, the mother said the abuse has had a "massive" impact on the lives of her family, and said: "It has made me a nervous wreck."

She added: "I feel as if I have let my children down, that I didn't protect them. I am now overly-protective of them. I try to stop them playing out."

Smith, of Park Lane, Darlington, admitted eight charges of sexual assault, and was convicted of a a further two as well as the count of rape.