One of the traces most sought after by police investigators at the crime scene is hair: analysis of your DNA can solve the case.
But body hair samples are not always useful, as it is essential that they preserve the hair bulb or the root. In addition, this method takes time, which can fatally slow down the investigation and facilitate the escape of the culprit.
For this reason, sometimes there is no choice but to resort to traditional techniques; that is, analyze the collected hairs under a microscope and compare them with those of the suspects. The problem is that their results are less conclusive than those of genetic tests.
A new study suggests pulling a thread that until now has not been taken into account too much: hair dye. As the authors explain in the journal Analytical Chemistry , investigators must bring to the scene a Raman spectrometer , an optical device with laser technology that locates tiny remnants of drugs, explosives, gunshot residues and bodily fluids.
The spectrometer immediately detects if the hairs are dyed , and what type of dye has been used, a clue that in the end can be decisive.
