Police may soon apprehend criminals using a completely different DNA sampling method to analyze evidence in the air.
Criminals knowledgeable about forensics will know how to clean a crime scene to erase DNA traces in an attempt to evade justice. However, new research indicates that the air itself and air conditioning units may still retain crime evidence, according to IFLScience on April 2.
Forensic technology is based on the fact that humans leave DNA traces everywhere they go, from saliva when we speak and cough to dead skin cells and hair.
Human DNA can be found in the air at crime scenes – (Illustrative photo: Shutterstock)
For decades, police have identified criminals by using DNA technology on samples such as tissues or semen found at crime scenes.
However, wearing gloves and cleaning the scene can effectively erase these valuable pieces of evidence. Therefore, searching for environmental DNA (eDNA) through other means may play a crucial role in cases involving knowledgeable criminals.
A small-scale investigation seeking traces of eDNA has been tested in two locations. One involved an air conditioning unit operating in four offices and four buildings, and the other was the air within these rooms. These locations were sampled at different times after cleaning and with varying numbers of people present over different periods.
The results showed that human DNA could be found in both environments. DNA collected from the air corresponded to individuals present in the room close to the sampling time, while DNA obtained from the surfaces of the air conditioning units appeared to be somewhat older. This suggests that the location of eDNA can provide insights into how a person used that space.
“The research indicates that human DNA can be collected from the air and from surfaces with circulating air, such as air conditioning units, and can identify individuals who frequent that space as well as regular guests“, the research team from Flinders University (Australia) stated.
Sampling air conditioning units could be used to identify individuals who use a room frequently or for long periods. Meanwhile, air sampling could help identify those who have used the room less frequently or more recently.
Although this is a promising advancement in efforts to prevent criminals from escaping justice, the research team noted that further studies are needed to determine the best locations for collecting eDNA.
The study was published in the journal Electrophoresis.
