Was the nickname given lawyer-detective Grace Humiston when she became prominent in New York’s 1917 Ruth Cruger murder case. The fascinating story is told in Brad Ricca’s biography Mrs Sherlock Holmes, which is as gripping and surprising as any great detective novel.
In an interesting episode, the wife of suspected murderer Alfredo Cocchi is being questioned
Wallstein kept his questions focused on the police activities in the case. … She [Maria Cocchi] silently stuck out her hand and produced a white card. Wallstein took it and turned it over. It read:
Take care of Alfredo Cocchi. He’s O. K. BILLY EYNON
When Wallstein read the tiny card out loud, the crowd nodded and the reporters wrote. Everyone knew that Billy Eynon was an active motorcycle cop. Wallstein was very familiar with these types of cards, though he wished that he were not. The holder of the card could show it to any motorcycle squad member who had pulled him over for speeding and walk away without a ticket. (p. 221)
Sketchy stuff. What’s more, 103 years later, the NYPD Patrolmen’s Benevolent Association is still handing out cards like this. Better yet, you, too, can get one on EBay!