When you are done doing something involving your hands, they tend to get sweaty. Sweat is actually an oily chemical that is constantly being produced by your hands. This chemical helps forensic teams to identify peoples’ fingerprints during crime scene investigations. Scientists are using the chemical in these fingerprints left at crime scenes to reveal the age of the prints, but there is still an issue: scientists can't tell how old the prints are.
The oily chemical that fingerprints produce reacts with oxygen in the air. Examining the changes and degradation of the chemical after oxygen exposure helps scientists calculate the age of a fingerprint.
When researchers analyze prints, they use something called mass spectrometry. This technique is used to identify atoms and molecules in fingerprints by their mass. The chemical from each print changes differently, from one day to the next. Some even show changes within seven days.
These analyses show how changes in a print within days matter. It also helps compare the age by using the chemicals that tend to increase or decrease when exposed to oxygen in the air. This could benefit a lot of forensic scientists, however, this project still needs to be tested in real life, not only in lab projects.
Forensic scientists also see how fingerprints react to different climates and surfaces to help them in investigations. In many cases, the project may fail or work. If it eventually does work, this project could be really helpful in many criminal investigations around the world.