Could Criminals Leave DNA Behind in the Air?
Forensic investigators usually look for DNA on objects that have been touched. New research suggests they may eventually be able to look somewhere else too: the air inside a room.
A study published in Forensic Science International: Genetics on 2 September 2026 investigated whether airborne environmental DNA, known as eDNA, could help identify someone who had briefly entered a home.
Testing DNA After a Simulated Burglary
Researchers collected 391 DNA samples from air, dust and surfaces across 22 households.
The homes were sampled after residents had left and again following a simulated burglary, where an intruder spent just 15 minutes inside the property.
Air samples collected 30 minutes later were able to detect DNA associated with the intruder. Detection rates varied considerably between the two laboratories involved, reaching 82 per cent in one laboratory and 36 per cent in the other.
How Does DNA End Up in the Air?
People continually release microscopic biological material into their surroundings through skin cells and other particles.
These traces can become suspended in the air and potentially be collected using specialised air sampling methods.
The study also found that combining airborne DNA with samples collected from dust and surfaces could provide additional information about people who regularly occupied or had previously visited a property.
A New Source of Forensic Evidence?
The researchers caution that airborne DNA is not yet ready to replace established forensic evidence collection methods.
Results were affected by factors including individual DNA shedding, household occupancy, cleaning practices, environmental conditions and differences between laboratories.
However, the research shows that airborne DNA could potentially become a complementary source of evidence, particularly where traditional biological traces are limited or absent.
The study also has Australian involvement, with researchers from Victoria Police and Forensic Science SA contributing to the work.
As forensic DNA technology continues to advance, evidence may no longer be limited to what investigators can see or what a person has physically touched. In the future, simply spending time inside a room could potentially leave behind another forensic trace.
Source: https://www.sciencedirect.com/science/article/pii/S1872497326001997