When Billie Frechette is covering Dillinger's escape from the Little Bohemia lodge, her weapon changes from a Tommy gun to a BAR 1918.
When the security guard comes out of the bank early in the picture, he shoots a gang member who is standing next to a car. If you look carefully, you can see that the gangster already has bullet holes and blood on his suit, perhaps from an earlier take.
During the Little Bohemia shootout when most of the gang is gathered in the lodge's lobby exchanging fire with the FBI, Nelson can be seen in the background loading a 50-round drum magazine into his Tommy gun. During his next close-up, it's loaded with a 30-round box magazine.
Notes at the end of the movie claim that Melvin Purvis shot himself with the gun he killed John Dillinger with. In fact, the gun used to self-inflict his fatal wound was given to him by his colleagues at the FBI when he retired in 1935, the year after Dillinger was shot.
John Dillinger like many Chicagoans in July went to the movies as much to escape the heat as to see the feature. The heavy overcoats worn by the FBI are out of season.
This movie shows both Pretty Boy Floyd and Baby Face Nelson being killed before Dillinger. Dillinger was killed first on June 22, 1934. Pretty Boy Floyd was then killed on October 22, 1934, and Baby Face Nelson was killed on November 27. 1934.
Homer Van Meter was killed after Dillinger in St. Paul, MN August 23rd 1934.
As with most biopics, some historical details have been altered for the sake of the narrative. See trivia.
Closeup of front page newspaper story heralding Dillinger's capture in Tucson is just a bunch of nonsensical paragraphs repeated over and over.
In the photo montage in the movie is a frontal shot of Warren Oates holding what appears to be a Colt Model 1911 pistol, which should be chambered in caliber .45ACP. The bore of the pistol is far too small. If the pistol is an actual handgun and not something like a pellet gun, it is either a Colt "Ace" model, or a 1911 modified with a conversion kit. In either case the pistol is chambered for .22 long rifle caliber, a highly unlikely choice for a gangster's weapon.
The National Guard troops guarding the Indiana jail that Dillinger escapes from in 1933 are equipped with M-1 Garand rifles. The Garand was not issued to regular US Army troops until 1937 and then at an initial rate of only 10 rifles per day. National Guard units did not receive them until American entered World War 2.
Late in the film, Dillinger (Oates) drives to a farmhouse in a Model A Ford and switches off the car radio. Radios were very rare in cars at that time and very expensive (depression era), costing about $130 when the car cost just $350-$400.
Aanachronism: In photo 12, a staged still (not seen in the film) with Ben Johnson, Warren Oates, Michelle Phillips and Cloris Leachman, a poster from "Rock Island Trail (1950)" is seen on the theatre wall. And in photo 34, with Oates, Phillips and Leachman, a poster from the 1937 Kermit Mynard western "Galloping Dynamite" is on the theatre wall.
when Dillinger gets arrested at a Tucson hoe-down, the shot right after Homer takes a photo of the two Policemen, a modern lighting stand can be seen on the left side of the screen hidden mostly by the tree.
when Purvis guns down Wilbur Underhill, the locked-off shot of the desolate house right after Purvis starts talking to Sam, a modern lighting stand can be seen at the extreme left side of the screen.
In the movie John Dillinger exists the Biograph Theater and turns right or north. In fact the alley he was shot in was to the left or 1/4 of a block south of the theater.
Harry Pierpont is called Harry Pierpoint by several characters.
Melvin Purvis was portrayed in the film as a 6'2" tough guy by Ben Johnson. In actuality Purvis was a pencil-pushing short nerdy fellow who supposedly trembled in fear trying to light his cigar at the Biograph Theater ambush.