Study Finds New Role for Cell Phones in Criminal Investigations

Cell phones – they store our bank passwords, photo albums, and private messages. But there’s more to a phone than what’s inside. A new study finds that trace evidence from the surface of cell phones could help create a suspect profile in a criminal investigation. Jill Bosserman reports.

BOSSERMAN 1: Scientists at the University of California, San Diego, took swabs from the surface of 39 people’s cell phones. They found molecules drawn from makeup and hygiene products, medications, and food. When they swabbed the same people’s hands and faces, the chemical profiles matched. Dr. Pieter (Pee-ter) Dorrestein (STEEN) leads the lab that did the study.

DORRESTEIN 1: We also saw a lot of personal care products, we saw a lot of food, we saw a lot of medications that people were taking, and that’s when we realized, those molecules must be transferred to objects we frequently touch, and the inside of those molecules could be useful for an investigative team. (0:18)

BOSSERMAN 2: Here’s how it works. Researchers compare the molecules they find on a phone to a database they’re compiling, which has about 18,000 molecules. Once they match the molecules to substances—like cosmetic products or medications—they can create a “lifestyle profile” for that person. And that could be useful in a criminal investigation.

DORRESTEIN 2: Learning the certain behavior of a given individual, is what helps a crime scene investigator trying to figure out, what are the types of people they should be looking for. And I think this is actually stronger than personality profiling in the fact that we actually have real molecules that give us that insight. (0:22)

BOSSERMAN 3: The caveat? The profile can’t tell you that a certain person committed a crime. But it can give you a general picture of the kind of person they are. Dorrestein (STEEN) says it’s a bit like drawing a composite sketch from a bunch of different descriptions.

DORRESTEIN 2: If you have a lot of witnesses, for example, and it’s fairly dark, they can create a sketch of what a person looks like based on all the different descriptions that, let’s say, 20 different people provide. (0:14)

BOSSERMAN 4: This sketch could narrow the pool of suspects. Gloria Proni teaches chemistry at John Jay College of Criminal Justice. She says the technique would need to be tested in a real case. For example, identifying what medication someone takes may be interesting, but it’s far from being all you need to convict someone.

PRONI 1: When you’re trying to convict a person—just for the fact that you’re detecting benzodiazepine, so the person may be depressed. It’s not enough for a full conviction. (0:09)

STOCKWELL 1: Normally, you’d be looking for fingerprints, you’d be looking for DNA… (0:05)

BOSSERMAN 5: Brent Stockwell is a professor of chemistry and biology at Columbia. His research uses small molecules to understand and treat diseases. Stockwell says the new technique is exciting because it uses chemistry to help us understand individuals.

STOCKWELL 2: …And now, you could be looking for the trace chemical signature of an individual, and it wouldn’t by itself be sufficient to identify that person – it wouldn’t be like a DNA signature, but it could give the investigator some clues about who they should be looking for. (0:17)

The project is still going. Labs from 120 countries have collected and sent data to UCSD’s crowd-sourced database. Right now, 17,000 individual registered accounts have submitted information, and the database is still growing.

Jill Bosserman, Columbia Radio News.