Professor Noah Fierer from the University of Colorado in Boulder found that everyone has their own "unique trail of bugs."
Fierer told ABC News in Australia:
Any two people only share about 13 per cent of their bacterial species in common so these are diverse communities and they seem to be very unique to each person.
In his study, Fierer clearly identified the computer with the owner. First, he swabbed the individual keys for bacteria. And then matched the bacteria with the bugs found underneath the fingertips of the owners.
The scientists wrote in their PNAS paper that even identical twins who share the same DNA profile have "substantially" different bacteria living and growing on their hands.
"This suggests that the collective genomes of [these microbes] may be more personally identifying than our own human genomes."
But this bacterial method is only 70-90 percent accurate, so it would have to be used with other evidence such as DNA. Michigan State University's Forensic Biology Laboratory, David Foran, says it's unlikely the bacteria will be used as a forensics tool. However, this doesn't mean it won't appear on CSI soon.