They kept the program a secret for four years, to make sure there weren’t any surprise issues.
In the demonstration I watched, Harley (the ESD sniffing dog) found 10 items in a room she’d never been in before. Some were obvious, like a phone under a couch, but others were inconspicuous devices that would be easy to miss, even for a trained eye. She even sniffed a coat hook that Halligan told me was actually a surveillance camera.
This technique was used to find child pornography in the home of Jared Fogle, Subway Spokesman.