Child killer Paul Smith, convicted of smothering to death Rosie May Storrie at a party, had a history of attacking other young girls - including one he abducted in a car.
Smith held Rosie down on a bed until she stopped breathing
He bound, gagged and blindfolded the 16-year-old before bundling her into the boot.
But she escaped without injury after he left her by the side of the road two miles from his home in Sedgebrook, Lincolnshire.
However, he was not prosecuted for the incident in 2002 after the victim's parents decided not to press charges.
Smith, now 18, was jailed for life on Thursday for murdering 10-year-old Rose May Storrie at a Christmas party in Normanton, Leicestershire, last year.
She had been attacked and left face down on a bed in the house - as her parents chatted and mingled with 60 guests downstairs.
Now, it has emerged that Smith, who suffers from a form of autism called Asperger's Syndrome, had attacked other youngsters.
The abducted girl's ordeal came less than six months after he attacked another child
who was just 12 years old when he turned on her in his bedroom and pinned her
face down on the bed.
She was brought before the jury and was in tears as she told police in an
interview played to the court how her hands were tied and she was blindfolded by
the older boy.
A third allegation was four or five years earlier when a 12-year-old girl
claimed she was pushed backwards on to a bed by Smith who then grabbed her
between the legs.
The alleged incident, which was referred to by counsel during Smith's early
appearances in connection with the murder, was gossiped about at school but no
complaint was ever made.
Smith was never prosecuted over two of the offences as both his
victims were close family friends who decided not to press charges.
The 16-year-old victim's family said they did not want any action taken because they thought Smith would be able to get help for his problems.
In a statement, the 16-year-old victim's parents said: "When considering whether or not to press charges we took into account what had happened during those 20 minutes.
"We also took into account the Paul we had known for eight years.
"Our daughter didn't want to bring charges against her childhood friend, Paul appeared to recognise that he had done wrong.
"We thought he probably needed help and that his parents would ensure he got it.
Rosie's parents now have a shrine to the little girl in their living room
"No police officer suggested we rethink our decision.
"Our view on whether or not to press charges was clearly a subjective one, but the police officers who were involved in taking (our daughter's) evidence agreed that we were doing the right thing.
"When, some months later, I signed a form agreeing that we would not press charges, the officer who brought the form also agreed and stated that he hoped this would enable Paul to get the help he needed.
"It is clear, however that several members of the wider Smith family did know the history of all of the incidents and thought it quite safe for him to be at the party.
"Most of the people who knew the most about Paul's history were probably at that party that night."
Rosie's father, Graham Storrie said: "I just can't believe that no charges were pressed at that stage.
"If something had been done by Lincolnshire Police at that point I don't think Paul Smith would have been around to murder my daughter."
Paul Smith: Accused of other attacks
A spokesperson for Lincolnshire Police told BBC News Online that an investigation was carried out and a file was completed and submitted to the Crown Prosecution Service.
According to the CPS it reviewed the evidence on the charge of kidnapping and it decided that while there was sufficient evidence for a realistic prospect of conviction, it was not in the public interest to go ahead with that charge.
Since Rosie's death, her family have set up a memorial in their living room to Rosie May.
Mary Storrie, Rosie's mother said: "We light the candle every night to remember Rosie May and we have done ever since she was killed.
"It just gives us some time to focus on Rosie May."
The family have also released a tribute CD of Van Morrison's Brown Eyed Girl - which her father, Graham used to sing to her as he rocked her to sleep as a baby.
Other charity events are also planned.
They hope the Rosie May Memorial fund will pay for a lasting tribute in the village to Rosie, such as a bandstand and also to raise cash for specialist equipment at the Sheffield Children's Hospital which fought to save the young girl's life.