Police focus on Holly's computer

The new National Hi-Tech Crime Unit is offering vital assistance to Cambridgeshire Police in the hunt for the missing girls.

The unit, set up last April, comprises detectives, forensic experts and computer consultants and will have aided the force's own specialists who have been studying Holly Wells's computer.

Sources are understandably reluctant to disclose the precise techniques they use, but it is known that police have the ability to capture data from cyberspace and trace emails to the computer and telephone line from which they originated.

Police say Holly's computer has given them a number of lines of inquiry and they will quickly have been able to see which websites Holly and Jessica Chapman accessed and whether they went on to use chatrooms, perhaps dedicated to their favourite football team Manchester United and player David Beckham.

If police are seriously pursuing the idea that they are dealing with a sex offender who has set out to lure the girls via the internet, they know that there are sophisticated paedophiles who are constantly trying to stay one step ahead of law enforcers by using encryption techniques to mask the identity of their computer and disguise their movements in cyberspace.

In spite of the challenges in the emerging arena of cyber crime, there is no doubt detectives start from a position of far greater knowledge today when dealing with sex offenders.

Since the Sex Offenders Register came into effect in 1997, all people convicted after that date have to tell police where they live. It means that Cambridgeshire will know how many offenders it has in its patch; publicly available data reveals that there are 266 registered sex offenders in the force area and 18,513 nationwide.

Some of these individuals will be designated as highrisk since they have committed grave sex crimes or offences involving children, and they are likely to have been under regular monitoring from police and probation officers.

Cambridgeshire detectives will have visited all known highrisk offenders in their area on day one of the investigation, a probation expert said. Other forces are certain to have been making checks on the most dangerous offenders in their area.