How Text-Messaging Slips Can Help Catch Murderers
Grant, Tim, The Independent (London, England)
AFTER DANIELLE Jones disappeared on 18 June 2001, a series of text messages were sent from her phone. Police were suspicious that the later messages in the series were not written by Danielle, and linguistic analysis was able to show that they were in fact more likely to have been written by her uncle, Stuart Campbell. Likewise, when Jenny Nicholl disappeared in 2005, a linguistic analysis showed that text messages sent from her handset were probably written not by her but by her ex-lover, David Hodgson. Both Hodgson and Campbell were convicted of murder, and the linguistic evidence played an important role in their prosecution.
In the Hodgson case, Professor Malcolm Coulthard was able to show that the suspect messages were stylistically close to the undisputed messages of Hodgson - features like the lack of a space after the digit substitution in items such as "go2shop", contrasting with "ave 2 go" in Ms Nicholl's messages.
This is powerful evidence. But soon, forensic authorship analysis may move from a skill based in expert intuition to a true forensic science. There has been considerable work in developing statistical and computational approaches to authorship analysis. One of the more successful approaches introduces the statistical metaphor of stylistic distance between texts. Texts which are charted close to each other can be linked to the same author, whereas for texts that are more distant, it can be argued that there is a lower likelihood of shared authorship. …