Garth was a henchman of Emile Dorian.
Garth abducted Selina Kyle for experimentation, finding her visiting the Gotham Zoo. He also callously knocked a zoo employee into the tiger pit to avoid witnesses.
Later, in Dorian's island mansion, Tygrus was practicing for his forthcoming fight with Batman, whereas Garth was seen firing shots at Tygrus.
After Dorian was arrested and his base destroyed, Garth was arrested.