I found this book at a book sale in Schroon Lake, thinking it was the novel that the film was based upon. However, the book is actually a novelization of the movie, and not a bad one at that.
Some of the names are changed, but the book essentially follows the plot of the movie. A bisexual Vietnam vet, tired of the same old grind and desperately needing money for his sweetie's sex-change operation, Littlejoe plans a quick heist of a bank that is supposed to have a large amount of cash on Thursday afternoons for a bakery's payroll on Friday. The robbery is quite well planned but, unfortunately, the schedule has been changed so that the cash is actually to be delivered Friday morning. Littlejoe and his reluctant partner, Sam, realize all their planning has resulted in a haul of only $4,000, instead of the $50-100,000 they expected.
Because of the low payoff, Littlejoe decides to hold the bank employees hostage for $1 million and a jet to Morocco. What follows is a circus of obnoxious crowds, reporters, food vendors, police officers, FBI agents and weirdos who call the bank with suggestions for the thieves, all on the hottest afternoon of the summer.
Once the FBI finds out about Sam, a two-time felon, and realize that he won't give up without killing someone, they give in to the bandits' demands. Littlejoe, Sam and the hostages load up into a limo which takes them to JFK airport where a jet awaits. After letting a couple of the hostages go, the remaining people in the car start to get out, not knowing that the driver is another FBI agent. In a quick flurry, the driver kills Sam with two shots to the head and Littlejoe is knocked to the ground and cuffed, thereby ending things.
Dog Day Afternoon is a quick read, very dirty and gritty, and quite enjoyable. I'm not sure if it's still in publication, but if you can find the book I recommend it.