Scientists reveal text messages helping to convict criminals

Sep 8 2008 by Laura Davis, Liverpool Daily Post

A talk at the BA Festival of Science today will reveal text messages are being increasingly used in criminal convictions. Laura Davis reports

WHAT happens when a murder has taken place but there is no crime scene to analyse, no fingerprints or DNA evidence that could point to a suspect?

This was the case when 19-year-old Jenny Nicholl vanished without a trace in June, 2005. Her body was never found, yet there was enough proof to convict her ex-boyfriend, David Hodgson, earlier this year.

The evidence? A series of text messages sent by the teenager’s mobile phone after her disappear-ance, which linguistic experts agreed had been written by Hodg-son to throw police off the scent.

“What happens is you’ve got a series of messages written over time but in the last six or seven you see a style shift,” explains Dr Tim Grant, deputy director of the Centre for Forensic Linguistics at Aston University, who is present-ing a talk on his research in Liverpool today.

“We can ask whether those last messages are written more in the language of the victim or more in the language of the main suspect.”

As text messages and email become increasingly popular forms of communication, they are also more likely to be used in crime, says Dr Grant, who is speaking at the BA Festival of Science taking place in venues across Liverpool this week. “Because the language of texting isn’t fixed – it’s more like spelling and punctuation conventions in Shakespearean English in that everyone can do their own thing.

“Individuals fall into habits of using rules such as one abbrev-iation rather than another and we can identify these.”

In courts until recently, forensic linguistics were used mainly as a form of expert witness, in cases where it could be argued that a witness statement or letter contained passages written by someone other than the person who signed it.

However, the science is now becoming a more popular form of evidence for the prosecution and we could eventually see special forensic linguistic units, like those run by police in Germany, being set up in the UK.

“It’s easier to cast doubt on something. If you’re working for the defence, you only have to create that doubt, but for the prosecution you have to prove something beyond all reasonable doubt,” explains Dr Grant, who has worked in the field for the past 15 years.

The most successful use of text message analysis has been in cases where police suspect a text has been written by someone other than the person it is claimed to be from.

More difficult is proving, without any additional clues at all, what sort of person could have sent a particular text.

“You can make tentative pre-dictions about gender. It might be used in an investigation, so you could say to the police ‘I think these messages are more likely to have been made by a woman’, but it would never be strong enough to go to court.

“Predicting age is even more difficult. It’s not true in text mes-saging that the younger you are the more likely you are to use text language.”

And for criminals who think that studying other people’s texts will enable them to copy them undetected, Dr Grant has a warn-ing: “When people have attempt-ed to disguise their messages, it has been relatively unsuccessful. An example is if someone is naturally a bad speller.”

THE BA Joseph Lister Award Lecture – Txt Crimes, Sex Crimes and Murder: the Science of Forensic Linguistics.

lauradavis