Justin was a teenaged vampire and a member of a rebellious pack that included his best friend Zack, who dated Janice Penshaw.
During Halloween in 2001, he and Jack met up with Janice and her friend Dawn Summers, having seen each at parties. The four where invited into the house of Kaltenbach where Justin fed on the old man before running off with his friends. He covered up what he did by claiming that he simply stole Kaltenbach's wallet. Justin and Dawn then bonded with each other because of his delinquency and her kleptomania. The two then made out in his car, Dawn experiencing her first kiss.
In the middle of their embrace, Justin vamped out and Dawn shortly then noticed it. With Dawn backing away out of the car, Justin explained that he really liked her. But before he could sire her, Rupert Giles, Spike and Dawn's sister Buffy arrived. While they fought with the rest of his gang, Justin approached Dawn in the woods, where he knocked her down before straddling her. She staked him with an arrow from a crossbow just as he leaned down and was about to bite her.