Isaiah Beard <sacredpoet@sacredpoet.com> wrote:
"Refuting the validity of this evidence to bolster the prosecution's
case depends on how far away that cell tower was. There are plenty of
reasons for a non-adjacent cell to take your call. Perhaps the
nearest cell was at capacity and could not handle your call, but your
phone happened to be able to pick up a not-so-nearby cell that had
slots free."
In the Huntley case I mentioned earlier there was just such an
example. Huntley's phone was picked up by a base station some way
off, but the prosecution brought in someone from the phone company --
Vodafone I think but I can't remember -- to show that because the
terrain (Soham, near Cambridge, in eastern England) is very flat there
was a good signal from the distant base station at his home, where he
did the murders. Someone from the phone company tried it out and
demonstrated it to the jury with complex maps showing the field
strength around the area. Google "Soham murder" and you should find
reports of the case if you're interested.
Meanwhile have a look at this article from The Guardian's Online
section in 2001
http://www.guardian.co.uk/online/story/0,,608434,00.html. Under UK
data protection law (which is matched in other European Union
countries) citizens have a right to see personal data held about them
by private companies on payment of a small fee.
In that article a journalist, S A Mathieson, showed how he tested the
law with the mobile phone company Orange and demanded to see the data
it kept on his locations when he made calls. Orange had to comply with
the Data Protection Act.
Mathieson wrote: "[Guardian] Online can now reveal that the base
station used by an Orange subscriber is retained at the beginning and
end of every call, whether outbound or inbound, including calls to
retrieve voicemail," and wrote later in the same article: "Orange
... currently retains location data for six months. Vodafone already
keeps it for a year, BT Cellnet [since separated from BT and renamed
O2] for "at least a year", and Virgin Mobile has retained it since its
foundation in November 1999.
It plans to hold such data for six years, citing financial
regulations. One2One [now T-Mobile] refused to disclose its retention
period. Other than this information, none of the networks would
discuss location data further than to say they complied with the law."
Alan Burkitt-Gray
alan@burkitt-gray.com
Burkitt-Gray (alan@burkitt-gray.com)