The phrase "inmate handlers" refers to individuals who are responsible for managing and overseeing prisoners or inmates in a correctional facility. Full definition
Alexandra Horowitz (Being a Dog); Dr. Susan Roecker, Animal Chiropractor; Prison Greyhounds: inmate handlers get dogs ready for adoption (itunes.apple.com)
«Inmate handlers learn to take responsibility for taking care of a dog and learning the specific job skills and life skills required in that, and the dogs become adoptable and hopefully find new homes and free up space in the shelters.» (shelterme.tv)
To sharpen his skills so he can be the best family dog in town, Edgar is currently enrolled in Heaven Can Wait's Pups on Parole program where he is learning basic commands while living with his inmate handler. (lessonsfromaparalyzeddog.com)