Fritz Ann Dietrich was first introduced as the Special FBI Agent in charge of tracking the flashy bank robber, Blackjack across the country. When Blackjack came to Tracy’s city to match wits with America’s top cop, Dietrich arrived to brief the police and aid in Blackjack’s capture. She hit heavily on Sam Catchem during her stay, regardless of his protests that he was a married man.
A month later the Major Crime Squad learned they had a mole in the police department and were looking for a quiet way to get a warrant on the Panda Talent Agency, the hideout of the new Mr. Crime gang. Tracy called Dietrich to obtain the warrant and she joined the squad and Tracy detective agency is raiding the hideout. During the epic show down between cops and villains, Sam was wounded by Doubleup and Fritz Ann shot the offender several times, subduing him. Fritz Ann was actually one of the few individuals involved that was not wounded or killed.
Since the Mr. Crime case, Fritz Ann has been made frequent appearances at police headquarters, usually to pass on FBI information relating to or foreshadowing a case Tracy is working on.