Dillinger's father was a grocer, reportedly harsh, and his mother died when he was young. As a teenager he was in constant trouble for fighting and petty theft. He joined the Navy, deserted when his ship docked in Boston, and was dishonorably discharged. He married in April 1924. Struggling to find work, he and an accomplice robbed a Mooresville grocery store, netting $50. Arrested and convicted, Dillinger was sent to the Indiana Reformatory and then Indiana State Prison. He served nine and a half years. Upon entering prison, he reportedly told the guards: 'I will be the meanest bastard you ever saw when I get out of here.' It was one of the few promises he kept.

Paroled on May 10, 1933, Dillinger wasted no time. Within three months he robbed a bank in Bluffton, Ohio. By early 1934, his gang included Baby Face Nelson, Homer Van Meter, and Tommy Carroll. They tore through the Midwest: a bank in Sioux Falls, South Dakota; the First National Bank in Mason City, Iowa; shootouts in St. Paul, Minnesota, where Dillinger was wounded in the left calf by a detective's revolver. At the Lincoln Court Apartments, Van Meter talked his way past agents by claiming to be a soap salesman before opening fire. The gang escaped from the FBI's ambush at Little Bohemia Lodge in Wisconsin when agents mistakenly fired on innocent civilians, giving Dillinger time to flee out the back. The newspapers loved every minute of it, printing accounts of his daring and charm that cast him as a Robin Hood figure.

On January 25, 1934, Dillinger was captured in Tucson, Arizona, and extradited to Indiana. He was jailed at the Lake County jail in Crown Point on murder charges. Local police boasted to newspapers that the jail was escape-proof. On March 3, Dillinger proved them spectacularly wrong, walking out with a pistol during morning exercises. Whether the gun was real or carved from wood and shoe polish remains one of the great debates in criminal history. Deputy Ernest Blunk swore it was real. FBI files say it was carved. A jail trustee believed Dillinger had whittled it from a razor and shelving in his cell. Dillinger's own attorney's investigator later claimed he had smuggled the gun in himself. Whatever the truth, Dillinger walked out of an escape-proof jail without firing a shot, and the legend was sealed.

By July 1934, Dillinger was hiding in Chicago under the alias Jimmy Lawrence, working as a clerk. He had undergone crude plastic surgery to alter his appearance and had his fingerprints burned with acid. It was not enough. Ana Cumpanas, a Romanian-born brothel owner facing deportation, offered the FBI Dillinger's location in exchange for immigration help. She revealed he would be attending a movie with her and a woman named Polly Hamilton. She agreed to wear an orange dress so agents could identify the group. On the evening of July 22, the trio entered the Biograph Theater to see Manhattan Melodrama, a crime drama starring Clark Gable. When Dillinger emerged at approximately 10:30 p.m., Agent Melvin Purvis lit a cigar to signal his presence. Dillinger spotted the agents, reached for his Colt pistol, and ran for the alley. Three agents fired. The fatal bullet entered the back of his neck, severed his spinal cord, and exited below his right eye.

Dillinger's body was displayed at the Cook County morgue. An estimated 15,000 people filed past the corpse over a day and a half. Four death masks were made from the original mold. He was buried at Crown Hill Cemetery in Indianapolis, where his grave has become one of the city's most visited sites, the headstone perpetually damaged by souvenir hunters. Dillinger's brief and violent career had an outsized legacy: J. Edgar Hoover used him as justification to expand the Bureau of Investigation into the FBI, developing new forensic techniques and investigative methods. The gangster who was born in an Indianapolis house and buried in an Indianapolis cemetery inadvertently helped create the most powerful law enforcement agency in the world. The gravestone gets replaced. The visitors keep coming.