About the film
The Dog is a 2013 documentary film co-written and co-directed by Allison Berg and Frank Keraudren, about the real-life story of bisexual bank robber John Wojtowicz that inspired the 1975 Al Pacino movie Dog Day Afternoon about his August 1972 attempted heist and 14-hour televised hostage situation in Brooklyn to pay for his lover's sex-reassignment surgery.
From the film's Wikipedia article (CC BY-SA 4.0).