Indiana "Indy" Bones reports for duty on a field investigation, in which the dog sniffs to detect human remains for a reopened cold case. Gloria Hillard/NPR hide caption

itoggle caption Gloria Hillard/NPR

Tom Robichaud launched his business, Discreet Intervention, six months ago. Here, he works his dog in a vacant office building, hitting on a cylinder containing cocainelike drugs. Pat Greenhouse/Boston Globe via Getty Images hide caption

itoggle caption Pat Greenhouse/Boston Globe via Getty Images