Another alter-ego for Frank was ‘Jimmy Perkins’, a city vagrant. Frank would venture out unshaven and ragged, loitering around known criminals. They would consider him harmless and speak about planned crimes in his presence. The only problem was that fellow police officers had no idea Jimmy Perkins was really one of their own, and would move him on or even arrest him. Jimmy’s most famous case was the attempted robbery at the Union Bank;

After a series of raids on banks in 1926, Frank Fahy, disguised as a vagrant, hung around a near-city factory complex and watched three Italian suspects hand-making tools he believed were for safe-breaking. None of the trio suspected the disheveled ‘vagrant’ wandering in and out of the factories was in fact a police officer, and one day Fahy heard them mention renting an office above the Union Bank in Castlereagh Street.

Frank quickly informed his seniors, and when police raided that office several nights later, they found a hole cut in the floor – and the gang working on the safe in the bank below. They had climbed down via a rope ladder. All were arrested.