The Clay County Sheriff's Department arrested Edward E. Smith, 45, Monrovia, Ind., after looking into a lead from a concerned citizen.
Detectives and deputies learned the air conditioning units had been scrapped and retrieved photos from the business where the units had been sold.
After interviewing Smith, who was a former employee of the humane shelter, about his involvement in the theft, detectives arrested him for the theft of the units, and he was booked in the Clay County Justice Center.
Smith is being incarcerated with a $7,000 bond with no 10 percent allowed. The case is still under investigation and additional charges could be filed.
Clay County Sheriff Mike Heaton said sometimes leads from the public don't actually lead to anything, but in this case it did.
"In this case, it paid off," he said. "We always ask for help from the public. They see and hear a lot. They are one of our greatest assets."
The Humane Society realized three air conditioning units were stolen sometime between Sunday evening and Monday morning.