New forensic test can predict hair and eye color of suspects

Illustration for article titled New forensic test can predict hair and eye color of suspects

Police looking to identify an unknown suspect often rely upon a technique called criminal profiling in hopes of gaining some potential insight into their psychologies. But now a new forensic technique called Hirisplex could soon allow investigators to take this process a step further by allowing them to predict certain physical characteristics of suspects — like their hair and eye color — after analyzing traces of DNA that were left at the crime scene.


The field of Forensic DNA Phenotyping (FDP) has started to take root in forensic biology — a set of techniques that are increasingly allowing police investigators to drastically narrow down a large group of possible suspects.

DNA analysis is not new to forensics. Unlike genetic profiling, which takes a fingerprint-like approach to investigations, FDP does not require any pre-exiting information about an alleged criminal. In genetic profiling, a pre-existing database of DNA is cross-referenced against new evidence left at a crime scene. The obvious shortcoming of this approach is that, like a fingerprint, the database has to contain the suspect's DNA in order to make a match.

The Hirisplex system, on the other hand, can make predictions about a suspect's physical profile from scratch.

Paul Rincon of the BBC explains how it works:

The test system includes the six DNA markers previously used in a test for eye colour known as Irisplex, combining them with predictive markers for hair.

In the study, the authors used Hirisplex to predict hair colour phenotypes in a sample drawn from three European populations.

On average, their prediction accuracy was 69.5% for blonde hair, 78.5% for brown, 80% for red and 87.5% for black hair colour.

Analysis on worldwide DNA samples suggested the results were similar regardless of a person's geographic ancestry.

The team was also able to determine, with a prediction accuracy of about 86%, whether a brown-eyed, black haired person was of non-European versus European origin (excluding some nearby areas such as the Middle East).

The study was published in FSI Genetics and can be found here.

Top image via PeterPhoto123/




If only there was a way to change your hair color to avoid detection.......