Based on experience with pets in treating depression among the elderly and in providing therapy to chronically ill children and adults, the JHCC brought two puppies to the mental health unit. It was only after the puppies became an established part of the treatment program that staff observed decreased aggression among the inmates. To confirm this perception, the staff examined security and clinical logs to determine if the empirical evidence showed a significant decline in aggressive incidents after the puppies arrived. There were 68 incidents of aggression in the 4 months before pet therapy, with 12 of them involving physical altercations. In the 4 months after the puppies' arrival, there were 39 incidents of aggression, with 6 involving physical altercations. Controlling for other variables, the study concluded that the pet therapy has had a significant impact on inmate mental states, particularly aggressive tendencies. A plan to expand pet therapy is under consideration.