Cameron Carter wanted revenge on a paedophile, so he stomped his head against a rock and left him unconscious in some bushland.
The teenage vigilante helped take the 20-year-old man hostage before bashing and dumping him on a dirt track.
Carter, 19, and three others became enraged after they found out the man had abused his four-year-old niece.
The group lured him to a meeting in regional Victoria in August 2018, punched him to the ground and forced him into a car, where the attack continued.
Carter, a 16-year-old boy, and a man and woman drove their victim to a dirt track, where Carter stomped on the victim’s head and pushed it against a nearby rock.