Sniffing the USB drive you're hiding

Even in the digital age, you can teach old dogs new tricks. In 1986, police trained the first dog in the world to sniff out arson with the help of Jack Hubball, who identified accelerants that the canines could focus on. He then moved on to help police train dogs to detect narcotics and bombs.

The chemist's latest trick? Getting dogs to pick up the scent for laptops, digital cameras and those easy-to-conceal USB drives. Devices such as these are often used to stash illegal materials like child pornography, which the United States' Federal Bureau of Investigation (FBI) says is growing fast. The agency estimates that some 750,000 predators are online at any given moment with victims often found in chatrooms and on social networks.

To crack computer crimes, the 26-year forensics-lab veteran based in Connecticut had to first identify the chemicals associated with electronic-storage devices. Hubball took circuit boards, hard disks and flash drives of computers and tested each component. He narrowed the analysis down to a single common chemical.

Two trainers, Mike Real and Mark Linhard, then worked with a couple of dogs who had flunked out of New York City's Guiding Eyes for the Blind programme, a black Labrador named Selma and a golden Labrador named Thoreau. They excelled at this new endeavour.

After months of training, the dogs were able to detect the odour of the chemical in people's hands, concrete blocks, metal boxes and clothing. The dogs also had to ignore distracting smells such as food and coffee. "Selma has found many devices such as digital cameras with flash cards, USB drives and external drives," says Detective George Jupin of the Connecticut State Police's Computer Crimes Unit, who is now Selma's handler. "The evidence she finds has furthered investigations."

Since going on her first assignment in October 2013, Selma has been involved in more than 50 search warrants with local and state police, as well as the FBI. In one search, Selma discovered a memory card buried in a drawer inside a sewing machine. Material on the card led investigators to establish links between a suspect and the victims.

While most of the material found by Selma is child pornography, she's also located fraudulent documents and assisted on a homicide where the suspect used software to find information on firearms. The other dog, Thoreau, joined the Rhode Island State Police, carrying out the same work.

Meanwhile, Hubball has moved on to his next challenge: identifying the unique compound in liquid crystal displays, which would be used to sniff out the LCD screens on hidden smartphones.

- Bloomberg