DNA testing is not the staple in crime scene investigations that the thirty-nine iterations of the “CSI” and “NCIS” shows would leave you to believe. However, DNA testing is a go to in many cases when investigators have little else to work with and is the standard for placing someone at the scene of a crime in lieu of other evidence like fingerprints. A new study shows that analyzing genetic mutations of the proteins found in hair could offer an additional forensic technique.
Proteins in strands of hair could prove more stable and accurate than DNA
A new study published this week in the journal PLOS ONE, suggests a breakthrough has been made in matching hair to a specific individual by looking at the specific proteins present in each strand that won’t match anyone else in the world.
The paper postulates that the analysis of these proteins could prove more accurate than DNA testing which often comes back as a “93% probable match” or some other number similar to this that certainly opens a window of doubt. The researchers are hoping that with further study that they may actually close this window. The technique in question would not be so much used in active crime scenes where, say, skin is pulled from under the nails of a victim, but rather the researchers believe it best used in the forensic analysis of human remains.
The lead author of the published study is forensic scientist at the Lawrence Livermore National Laboratory (LLNL), Brad Hart, who calls the technique of protein analysis a future “game changer.”
“We are in a very similar place with protein-based identification to where DNA profiling was during the early days of its development,” Hart told The Washington Post. “This method will be a game-changer for forensics.”
“We are in a very similar place with protein-based identification to where DNA profiling was during the early days of its development,” said Hart.
Just another tool for forensic teams
Protein analysis in hair is very much related to DNA, but hair is considerably more stable and doesn’t suffer from contamination or degradation as DNA does. This degradation can simply be a matter of time when DNA is exposed to prolonged environmental factors or simple chemical processes.
It’s for this reason that hair samples were used to identify human remains that go back nearly three centuries.
“Because protein is more abundant and more robust than DNA, this potentially opens up enormous avenues of research in bioarchaeology and forensic science that couldn’t have been tackled before,” said Andrew Wilson at the University of Bradford in England in an interview with New Scientist. It was Wilson who provided the hair samples to Hart and his team at the Lawrence Livermore National Laboratory.
The researchers at the LLNL acknowledge that, while they discovered 185 protein markers across 82 hair samples, more research must be done with a larger sample size that ideally would be more varied to learn more about mutations. Additionally, the team’s sample size was considerably bigger than what would likely be left at most crime scenes.
“For this to be used as a forensic tool, we need to accomplish two things: we need to reduce sample size to a single hair, and we need to nail down the biostatistics and determine the best way to apply the product-rule,” said Glendon Parker, who is a biochemist at LLNL.
“The best-case scenario is you will eventually have, in five to 10 years, a complementary but separate method than we currently have to correctly identify or to exclude the right person involved in a crime,” said Glinda Cooper, director of science and research at the Innocence Project, which has seen the exoneration of many convicted of crimes and lead to a moratorium on the death penalty in the State of Illinois.