The dirt and secretions that users have on their hands rubs on their phones and leave clues behind about the owner's identity, his daily habits, the places he's been, his lifestyle, medical treatments, and more.
This is the result of a recent scientific paper titled "Lifestyle chemistries from phones for individual profiling," which argues that mass spectrometry (MS) can be used to analyze molecules and chemicals from a user's hand and from a phone's screen and back side.
The MS analysis can then provide details to law enforcement forensic investigators that can tie a device to suspects, similarly to DNA and fingerprints evidence.
This technique isn't only limited to smartphones or tablets. Researchers argue that the same technique can be used for all sorts of objects such as pens, keys, handbags, jewelry, or other.
If law enforcement doesn't have a suspect in custody to compare chemicals and molecules found on evidence, then the technique can be used to draw a profile on possible suspects.
For example, the molecules found on a phone can tell police if the suspect wears makeup, what type of soap he uses, if he's on medication, what type of medication he's taking, if he drinks tea or coffee, if he recently traveled to exotic locations, and more.
Researchers claim that during tests, they've successfully used mass spectrometry to tie 39 devices to their rightful owners.
Scientists also claim that the technique works with chemicals that were left on the devices six months before a sample was lifted, and the accuracy grew as more chemicals collected on the phone.
Even if investigators can't access password-protected devices, in some cases, there might be more evidence on the phone's screen than behind it. Are you wiping your phone's screen yet?