DNA evidence can't tell identical twins apart in rape case

Identical twins in the UK have both been charged with raping a teenage girl, even though forensic tests cannot prove which one carried out the attack.

British prosecutors have formally charged two men, Mohammed and Aftab Asghar, 22, with a single offence, but caution that "only one of the defendants faces trial." Both men were arrested after traces of DNA were found at the crime scene.

Identical twins, because they were spawned from the same fertilized egg, share the same DNA.

Police investigated after a 17 year-old girl claimed she was sexually assaulted in a park near Reading, Berks, on Guy Fawkes Night 2011. The detectives, unable to distinguish the two men according to DNA evidence alone — but knowing it had to be one of them — decided to charge both.

Police and Crown prosecutors are now trying to figure out if they should continue to pursue the case against the Asghar brothers. They've asked the judge for more time — but they have their work cut out for them. Scientists have learned that tiny genetic changes can occur to cells early on, which can account for subtle differences as twins grow older, but these changes are incredibly difficult to detect.

It may be a case where the science isn't quite there yet. So regrettably, assuming there isn't enough evidence to pinpoint one of the two, the charges may have to be dropped.

Interestingly, this isn't the first time this has happened. Earlier this year, two identical 24-year-old twin brothers were arrested on rape charges in France after DNA tests could not tell them apart.

This is an interesting development from a futurological perspective. Should human cloning ever take off, incidents like this could occur with regular frequency. But hopefully by that point it'll be easier to distinguish individual DNA (e.g., cellular and epigenetic changes).

[Via Telegraph, Mirror]

Image: INS News Agency