Andrew Angus grabbed the 14-year-old victim, pinned her against a wall and put his hands on her neck during a sexual assault.
The 46-year-old also held the girl’s mouth and struck her on the head during the attack near to Falkirk’s Dollar Park.
He had earlier been placed on a sexual offences prevention order at the town’s sheriff court banning him from approaching or communicating with females under 18 without the prior consent of an offender management unit.
Angus admitted the sexual assault committed on April 9 this year and breaching the order when he appeared at Falkirk Sheriff Court.
But Sheriff John Mundy sent him to the High Court for sentence because he considered it might be a case where an Order for Lifelong Restriction (OLR) was required.
Angus’ counsel Shelagh McCall argued against the imposition of an OLR – under which a judge sets a minimum jail sentence but an offender is only ever released if parole authorities are satisfied on public safety issues – when he appeared at the High Court in Edinburgh.
She said for a long part of his life Angus did not commit crimes. She said: “His first offence wasn’t committed until he was 43 years of age.”
Miss McCall said the change in his behaviour was largely as a consequence of excessive drinking by Angus.
She said: “He has acknowledged to the social work department repeatedly that he does not understand what is going on and needs help.”
But she said he had begun to address that problem and counselling had begun and he was preparing to undertake sex offender group work under a community order imposed on him.
Miss McCall said that a background report on Angus pointed to the need for “a long period of intervention, monitoring and supervision”. She argued that could be done by imposing an extended sentence on him involving a period of imprisonment followed by supervision in the community.
Lord Glennie told Angus: “I think you recognise this was a very serious offence. This was a sexual assault on a 14-year-old girl when you were already the subject of a sexual offences prevention order.”
The judge told him he would have jailed him for six years for the crime, but the prison sentence would be reduced following his early guilty plea. He also ordered that Angus be under supervision for a further three years.
Lord Glennie said: “The period of supervision is a serious matter and there must be compliance with the programmes you are required to take part in.”
The judge said the sheriff had been right to take the view that the case should be sent to the High Court with the view to the possibility of an OLR but he was persuaded he did not need to go as far as that.
Angus, a prisoner in Glasgow’s Barlinnie jail, was placed on the sex offenders register indefinitely.
Last year, Angus subjected another youngster, who was under the age of 13, to a sickening assault when he groped her in Falkirk Howgate Centre on March 19 and also attempted to “chat up” three girls under the age of 12.
That offence saw him placed on a supervised community payback order for three years and ordered to complete 200 hours of unpaid work within 12 months and attend the Scottish Government’s Moving Forward: Making Changes treatment programme for adult male sexual offenders considered as representing a significant risk of committing similar offences in the future.