A judge has questioned how a paedophile police officer was allowed to keep his job and carry on abusing a girl despite being caught taking photographs of children eight years earlier.
Disgraced Cambridgeshire Police sergeant Nick Lidstone, 55, admitted a series of rapes and child sex attacks relating to one victim at Norwich Crown Court last month.
The victim, who cannot be named for legal reasons, reported her years of abuse - which culminated in being raped as an adult - earlier this year.
Today it emerged Lidstone was arrested eight years ago for taking "up-skirt" pictures of children with a spy camera in a branch of Tesco in Royston, Hertfordshire.
He was given a conditional discharge after pleading guilty to a minor public order offence at North and East Hertfordshire Magistrates' Court in 2005. Because he was not charged with a sexual offence, his name was not placed on the sex offenders' register.
His abuse of the girl escalated and all of the most serious attacks happened after this offence, the court heard.
Sentencing him to 14 and a half years for the latest offences, Judge Anthony Bate said he had used his victim as a "sexual toy". He placed Lidstone on the sex offenders' register for life.
He added: "You have one previous conviction which has two worrying aspects: firstly, the nature of the offence and secondly, the fact you were convicted under public order legislation when quite clearly these were serious sexual offences.
"You had armed yourself with a covert camera and were found taking pictures of children. Why on earth you were not charged under the sexual offences act, I do not know.
"Whoever took that decision, it allowed you to carry on as a police officer."
The judge added that because he was convicted of a public order offence, nobody had looked more closely at Lidstone's relationship with children and a chance to detect his abuse was missed.
Despite undergoing therapy to address his sexual deviancy, Lidstone carried on abusing his victim who suffered significant psychological harm.
Judge Bate said that Lidstone's apparent cooperation with therapy showed how he was able to "manipulate experts" into believing he had an ordinary sex life.
It was not until last month when he admitted the abuse that he was dismissed from his role at the force's headquarters after 30 years of service.
Prosecutor Andrew Shaw said the pictures taken in 2005 were of "young children" and there was some doubt over whether the worst of the images were found.
Kerry Broome, mitigating, said Lidstone had agreed to undergo counselling in order to keep his job.
His role with the police had not involved regular contact with children.
Lidstone, from Heslerton Way, Barrington, Cambridgeshire, pleaded guilty to 13 offences - including three counts of rape, three counts of indecency with a child, various sexual assaults and taking an indecent photograph of a child - in November this year. He denied six other counts, which were left to lie on file.
Mr Shaw told the court Lidstone started grooming the girl when she was nine. He would expose himself to her, show her pornography and take indecent photographs.
"This was serious sexual assault," Mr Shaw said. "The abuse was more or less continuous and culminated in rape when she was a young adult."
His victim was unable to make a statement to the court, saying she was so distressed that even the thought of it made her physically sick.
One witness who knew the victim described how her life had been "ruined".
"She has never been able to integrate or make friends," he said. "He has shown himself to be lying and manipulative."
Dressed in a black suit, Lidstone broke down in tears in the dock as details of his abuse were read out.
Referring to the latest offences, Miss Broome said her client had been "infatuated".
She said that, with expert help, there was no reason he should pose any further danger to the public.
"He is very well aware of the shame he has brought on the police force and his 30 years of service are over," Miss Broome said.
Speaking after Lidstone was dismissed last month, Deputy Chief Constable Alec Wood said: "This was an appalling crime where the victim was put through a horrendous ordeal over a prolonged period."
Cambridgeshire Police have not yet responded to the judge's comments.
Mr Wood welcomed the sentencing and said: "We want the public and our own employees to feel confident about raising concerns about the conduct of our officers and staff.
"We will always investigate these cases thoroughly and ensure any offenders are brought to justice."
Jon Brown, who heads the NSPCC's programmes for tackling sexual abuse, said: "It seems quite incredible that this officer wasn't charged first time around with a sexual offence.
"If he had been it's possible these later, more serious crimes could have been stopped sooner or even prevented in the first place.
"The tragedy is that a young girl has suffered terribly at this man's hands when he should not have been allowed the freedom to act in this appalling way.
"This underlines the importance of taking all sex offences extremely seriously and making sure the right course of action is followed through.
"It would only be right for the police authority to take a look at how he came to be charged with a minor offence all those years ago and to ensure it doesn't happen again."
Cambridgeshire chief constable Simon Parr said: "At the time of the offences in 2005, the case was reviewed and the then-deputy chief constable decided Lidstone be placed on restricted duties.
"If we were faced with the same decision today, a more severe sanction would be imposed."