The purpose of a revocation hearing is not to determine defendant's culpability, but rather to decide "whether the alternatives to incarceration which have been made available to a defendant remain viable for him." People ex rel. Gallagher v. District Court, 591 P.2d 1015, 1017 (Colo. 1978) (en banc). Revocation will result when the continuation of probation conditions would be at odds with the need to protect the public and society's interest in rehabilitation — in other words, when the rehabilitative purposes of probation have failed and defendant is a threat to society.