Commissioner James Gordon is the police commissioner for the Gotham City Police Department, and a close ally of Batman. After the Joker took over Arkham Asylum, Gordon met with Batman on the roof of the GCPD building to inform him about what had happened.
He was startled to see the Turtles accompanying Batman, Robin and Batgirl. After briefly talking to himself about retiring somewhere where the giant turtles didn't talk, he informed the group about the events at Arkham. Gordon was somewhat unhappy when the entire group disappeared silently when he looked away, only to be startled when Michelangelo revealed he was still there.