Newer CCTV pictures could endanger other teenagers

Ralph Bulger, father of the murdered child, has called for restraint, fearing the possibility of such cases of mistaken identity.

"We do not want to see the wrong people hunted and attacked, because at the end of the day that would be in James's name," he said.

While the faces of the two killers as they looked when arrested aged 10 are familiar to millions, a court injunction concerning more recent photographs of the pair means potential vigilantes have little idea of who to target.

Picture imperfect

Ironically, the posting on the internet of a picture purporting to be of Robert Thompson taken from a CCTV camera may actually increase the likelihood of misdirected attacks.

Attempting to identify strangers from photographs - and particularly low-quality CCTV footage - is not something at which people excel, says facial recognition expert Professor Michael Burton.

Naming and shaming put the innocent at risk

"All our experiments suggest people are rotten, absolutely rotten, at identifying faces they are not already familiar with from photos."

While we can readily pick out friends, relatives or acquaintances from even the grainiest shots, previously unknown faces prompt us to wrongly concentrate of "superficial" features, says Professor Burton.

"People will focus in on characteristics such as the hairline or hairstyle, which change over time. Thieves who steal photo IDs find that simply by wearing the same clothes as the person in the picture, they can pass themselves off as the rightful owner."

Name and shame

When the News of the World published a series of photographs of convicted paedophiles last year, a 49-year-old Greater Manchester man was mistaken for one of them by an angry mob because of a neck brace he wears for a spinal disorder.

Iain Armstrong's home was besieged by up to 300 vigilantes because the brace was similar to that worn by a convicted sex offender "named and shamed" by the paper.

Innocent victim: Iain Armstrong was wrongly targeted

Professor Graham Davies, an expert in the legal use of videotaped evidence, says that given our "extraordinarily poor ability" to make accurate identifications based on photos, he is willing to "confidently predict this will happen once again with the Bulger case".

That the picture of Thompson is said to come from CCTV footage further increases the chances of misidentification, he says.

"These cameras tend to be positioned at some height, often at the tops of buildings. This causes distortion and adds to the loss of information viewers can gain about an unfamiliar face."

Distorted view

Professor Davies also suspects that so-called "ageing programs" may be used to turn the photos of the killers as they were in 1993 into approximations of what they look like today.

"These things work on averages. Sometimes they are accurate, sometimes very inaccurate. If you try to simulate what an 18-year-old looks like from a photo of a 10-year-old the possibility of getting it very wrong is quite high".

Public anger could fuel misidentifications

The emotions the Bulger case stir may also contribute to misidentifications, says Professor Davies.

"There will be people who wish very much to identify these boys. Such strength of feeling can only crank up the possibility of a perfectly innocent teenager being mistaken for one of them.

"I have found that when is comes to identifying strangers people are often very confident, even when they are very wrong."