Mack worked for Lex Luthor as a Luthor security guard.
Season Six[]
He became Lana Lang's stalker and took a picture of her in her room. He then sent her a negligee with a card saying "I want you to wear this when I kill you." He also was the one that killed Brady and Esposito so no one would find out that he was Lana's stalker. He tried to kill Lana when she was alone at the Luthor Mansion. He and Lana fought on the roof of the mansion in the snow and fell through a skylight in the process. Mack died from the fall, but thanks to Clark Kent's intervention, Lana escaped unharmed.