In Dog Day Afternoon, what was the real name of the robber portrayed by Al Pacino?

In Dog Day Afternoon, Al Pacino portrays bank robber John Wojtowicz.

The 1975 film dramatizes Wojtowicz's attempt to rob a Brooklyn bank on August 22, 1972. The screenplay changed his name to Sonny Wortzik, which is why viewers can easily confuse the fictional character's name with the real robber's identity. Wojtowicz carried out the robbery with Salvatore Naturile, and the incident became a lengthy media-covered standoff.

Sidney Lumet directed the film, while Frank Pierson adapted a Life magazine article by P. F. Kluge and Thomas Moore. The production took considerable dramatic liberties, but its central robbery and hostage situation were based on the documented event. The film also became known for its portrayal of Wojtowicz's motive: he wanted money connected with gender-affirming surgery for his spouse.