A sex offender who stabbed a schoolgirl to death was not monitored after leaving prison because he changed his name, according to a report.
Sandy Hadfield's body was found in Boultham Park
Timothy Cuffy, 39, plied 13-year-old Sandy Hadfield with alcohol before taking her to a secluded park and cutting her throat with a Gurkha knife.
Cuffy had moved into the area a year before the killing in July 2002.
The independent report found he hid his criminal record from the authorities by using the surname Barnett.
Cuffy's new partner and her three children were also unaware of his previous convictions, which included indecent assault on a minor.
The report looked into how the man came to be in Lincolnshire without any supervision after his early release from a six-year sentence for burglary and assault on a blind woman.
It followed a two-year investigation by the Lincolnshire Safeguarding Children Board.
The report also found vital information about Cuffy was not shared between the Probation Service, the police and health authorities who all had contact with him prior to the killing.
Avril Price, who chaired the case review, said his criminal past should have been "communicated between every agency with which he came into contact".
She said the case could be compared to the Soham inquiry into the deaths of Holly Wells and Jessica Chapman, where it was found that killer Ian Huntley - also a sex offender - was able to move county without being checked.
Cuffy denied murdering the teenager
Cuffy had denied the killing, saying in interviews that he was cycling in the park when he found the girl's body.
The investigation discovered he was a Schedule 1 offender following his conviction for indecently assaulting a girl under 16 in 1992.
Because of the date of his conviction, he was not listed on the sex offenders' register allowing him, as he admitted to the investigative panel during interview, to "disappear".
Despite this conviction, when Cuffy - who also has a long-documented history of mental illness - was released from jail in October 2000 his licence period had expired.
That meant he was not under any statutory supervision by the Probation Service.
He returned to his home town of Derby and registered with a GP who referred him to a psychiatrist.
The report found that despite his background and the fact that Cuffy told the psychiatrist he was a sex offender, no risk assessment was carried out and he was released back into the care of his GP.
When he moved to Lincolnshire under the name Barnett the information was not passed to the health authorities in the county and he was able to conceal his past.
His background also went unchecked - because of his identity change - during two encounters with Lincolnshire Police and during contact with social services in relation to his partner's children.
Ms Price said that Cuffy, when interviewed by the panel, said that only his incarceration in jail could have prevented the murder.
Following the publication of the report, Sandy's mother Jackie James-Clarke, 36, said she was "dumbfounded" that a sex offender was able to change his name and go unchecked.
She said: "A lack of communication was the key in this investigation. Let us hope that Sandy's death will not be in vain.
"This man will continue to be a danger forever and I hope that he will never be released from prison."
Cuffy was found guilty of murder in June 2003 and later ordered to serve a minimum of 20 years in prison.