Casper Sterling was a member of the Followers of the Guardian.
On August 11, 2012, Sterling was at the Midnight Theater for the Lottery. Unbeknownst to him, the event had been infiltrated by Shadowhunters. He asked Cristina Rosales to dance; when Julian Blackthorn tried to refuse for her by saying she was his girlfriend, Sterling pointed out that he was a Blue—that he had considerable sway in the group, both for being part-werewolf and for being a member of the Followers for at least six months—suggesting that Jules and Cristina watch their attitudes. Cristina then obliged and begrudgingly danced with him. Sterling acted like a pervert, much to her chagrin.
During the Lottery, Sterling's number was chosen for "the hunt." Emma Carstairs and the other Shadowhunters went to him and protected him, thinking being picked for the hunt would mean he would be the target of the Followers.
He later contacted one of the new members named Wren and set up a meet with her, realizing that the girl had no clue that he could kill her for the hunt. On the same day, Cristina and Emma had tailed him and chased him to their meeting. Though Diego Rosales, another Shadowhunter who'd been investigating him, tried to stop him, Sterling proceeded to murder her, making her the thirteenth and penultimate kill necessary for the Guardian's ritual. Before he could be taken by the Guardian, he was subdued by the Shadowhunters.
He was captured and taken to the Los Angeles Institute and was interrogated along the way; though he was reluctant to give the information, Diego scared him into giving some up. Upon arrival at the Institute, they found the Followers surrounding the place demanding for Sterling's surrender. Sterling realized that he would be killed for giving up their secrets and begged the Shadowhunters to take him into the Institute, where he would be safe. When others were distracted, he was killed by the Guardian's magic, and, because Belinda did not know which hand was used to commit murder, she cut off and took both of his hands.
Sterling was arrogant, perverted, and greedy for power. Johnny Rook called him a "scumbag" and said that he had multiple identities and was difficult to find. In spite of his strong physique and bad attitude, he was cowardly and weak-willed.
Sterling had bleached blond hair. He was tall and appeared to be about twenty five years old.
Skills and abilities
- Increased speed and strength: Being half-werewolf gave Sterling increased speed and strength.
- Lady Midnight (first and only appearance)