The phone belonging to Claudia Lawrence was still active four hours after she failed to turn up to work, it has been reported.
The chef’s Samsung D900 handset connected to a mast next to her place of work at University of York at 10am, when her manager called and left a voice message.
That is one reason why police believe her killer was known to the 35-year-old chef.
A source close to the North Yorkshire Police investigation told the Sunday Times:
Her mobile phone never left the area of York.
This is part of the reason why the police believe she fell victim to an attack by somebody that she knew who was familiar with the area.
Claudia’s shift was due to start at 6am on Thursday, March 19, 2009, but she never arrived.
According to the paper, the call from her manager at 10am puts her handset within a nine-mile stretch between the university and Tockwith – and which includes her Heworth Road home.
It reports: “Telephone records show that two hours after Claudia’s manager placed the call, her mobile phone was switched off at 12.10pm.
“The records at her network provider are believed to show what experts call an ‘explicit detachment’, meaning her phone was able to send the network a record that it was being powered down properly before turning off.”
The paper also quotes Colin Sutton, a former detective chief inspector who carried out extensive mobile phone inquiries while investigating the crimes of the serial killer Levi Bellfield.
Mr Sutton told them:
What may have happened is that the phone rings out at 10am and goes to voicemail simply because there is nobody there.
Then whoever it is, possibly the suspect, looks at the phone at 12.10pm, realises there is a missed call, realises the phone is still switched on and then switches it off.
That is one explanation. However, just because her phone rings at 10am, it doesn’t mean she is with her phone at that point. She could be absolutely anywhere. But what you have to do as an investigator is treat it as if that is her location until you can rule it out.
Once realising Claudia has a missed call, the most likely thing you would think a suspect would do is smash it or break it or throw it in the river, which would provide the network with an implicit detachment record.
However, that didn’t happen. It appears what we get here is an explicit detachment, meaning the suspect had the calmness of mind to think: ‘I’d better switch the phone off in the normal way.’
In the Acomb area
Phone records also show Claudia was in Acomb in the weeks leading up to her disappearance. Police are trying to trace “a person or persons” she may have been in touch with in that area.
Her phone has never been recovered.
Police focused on Claudia’s social life, including at the Nag’s Head pub a few doors down from her home, when investigating her disappearance.
Nine people have been arrested or interviewed under caution by detectives. Police submitted files to the Crown Prosecution Service in relation to some but there wasn’t enough evidence to bring charges.