CONNECTICUT – Police K9 units have been deployed for a myriad of reasons during their illustrious careers in law enforcement. Now you can add electronic detection to the list.

Various police agencies in the US are using working dogs to sniff out thumb drives, phones, and other electronics. The training is similar to other detection work, but they are being trained to locate the faint chemical smell of electronic devices, reported CNET.

It’s a lesser-known use for the K9 programs around the country. Actually, it isn’t new. It was kept secret for years so that authorities could catch unsuspecting crooks without running into complications and so they could be sure the dogs weren’t making mistakes.

One case in 2015 did bring attention to dogs finding hardware through their olfactory senses. A Labrador retriever named Bear uncovered a man’s flash drive that contained child pornography, which helped make the case for the man’s conviction. This convicted defendant in this case was Jared Fogle, the former Subway spokesman. The district attorney called the discovery vital to Fogle’s conviction.

Kerry Halligan, a K9 instructor for the Connecticut State Police, told CNET that out of every 50 dogs tested, only one usually has a strong enough nose to identify the weak scent in electronics; specifically, they’re looking for the chemical compound triphenylphosphine oxide, which can be found in all gadgets that contain memory.

Moreover, Halligan said that electronics are harder to sniff out than bombs, drugs, humans, or flammable liquids. In particular, Labrador retrievers tend to have the excellent snouts that are required for the job. Dogs that are able to detect the scent are known as electronic storage detection (ESD) dogs.

The Labrador retriever Harley gets fed a few pieces of kibble for each device she sniffs out. On days when there’s nothing to search for, her handler, Detective Brett Hochron, with the Westchester County (NY) Police, will train her by hiding devices throughout the house. Once a week, she gets a treat day where she’s fed without having to earn it. But otherwise, they keep her on a tight regimen so that she’s motivated to search for thumb drives.

The dogs can find SIM cards that have a log of phone calls, find friends’ iPhones to replace the Apple feature, or even identify surveillance cameras in odd places like a coat hook. There are at least 17 of these ESD programs in the US that are used by local police and the FBI, and reports about the programs have increased in the last three years following the case with Bear.

Until they retire, all food-motivated search dogs are allowed to eat only after smelling the chemical they’ve been imprinted on. That keeps up their work mentality.

electronic detection

Detective Brett Hochron, with the Westchester County (NY) Police, and his partner Harley. (CBS New York YouTube video)

Harley gets fed only during searches, when she’ll get a handful of kibble for every device that she finds. If there’s no investigation, Hochron will find new search opportunities, like getting a friend to hide electronics around the house. One friend even asked Hochron if Harley could help find a missing iPhone after its battery died. (The family found the phone before Harley had a chance to look.)

“From the day she starts training to the day she retires, she will never eat out of a bowl,” says Halligan.