Even before the Soham trial, professionals in the child protection field had expressed concern about the inconsistency with which information on someone's background was made available.
By Jon Silverman
Home affairs analyst
In one unreported case last year in the North East, a teacher was able to get a job despite having been sacked from his previous post for inappropriate behaviour with a pupil.
Huntley's credentials were checked when he applied for the Soham post
The new employer did the proper checks through the Criminal Records Bureau but they all came back negative.
Russell Lee, the regional child protection co-ordinator, says: "The CRB is only as effective as the information it can access.
"If the information is not held anywhere, people who are clever and devious, can still slip through the net."
So, what information is held - and what is the legal position about releasing it?
Highest level checks
Someone applying for the post of a school caretaker should be subject to the highest level of check by the CRB - the so-called "enhanced" disclosure of information.
This is reserved for those who may have unsupervised access to children.
The information held may go well beyond convictions and would include "soft intelligence" such as unproven allegations or acquittals.
Despite the existence of the Human Rights Act and the Data Protection Act, this information may be passed on to a prospective employer because child protection is paramount.
But lawyers note that the question of how long such information may be kept on a person's file is fast becoming a contentious issue.
Human Rights Act
Employment barrister, Yvette Genn, is getting an increasing number of calls from people wanting to know how such damaging intelligence can be deleted.
"You can now apply to the Care Standards Tribunal to have information weeded out. Because in some cases, it may be a wholly unfounded allegation based on one anonymous source."
The Human Rights Act may come into play, she adds. "The HRA is a balancing act between the privacy rights of an individual and the well-being of society.
"But if you could prove that the holding of such information was disproportionate, you might have an arguable case."
Interestingly, none of the child protection charities has a policy of asking potential staff if they have ever been accused of an offence.
Chris Atkinson, policy adviser of the NSPCC, speculates that this may well be because of the Human Rights Act.
"I think you could only ask such a question if you could show you had very good grounds for doing it. It couldn't be a fishing expedition."
She believes a review is needed of the categories of people who should be subject to routine background checks.
"The CRB interprets unsupervised access to a child in a purely physical sense but what about chat room moderators and telephone counsellors?"
And the crime reduction charity, NACRO, would like to see clearer guidance from the Home Office and Department for Education about the kind of information which employers are entitled to seek.
Since roughly a third of sexual crimes are committed by people without a previous conviction, it is inevitable that some people with apparently excellent credentials but sinister intentions are going to get jobs working with children or vulnerable adults. And we will only know when it is too late.