Garret grew up in Washington State, and attended the University of Washington where he studied journalism. He went on to study acting at New York University's graduate acting program. He appeared extensively on and off Broadway and around the country before he began pursuing film and television roles.
He has two brothers. Brett, a teacher. And Eric, deceased.
Garret has worked on such productions as Criminal Minds, Raising Hope, and Law & Order: Special Victims Unit.