Later, the Federal Bureau of Investigation (FBI) announced that Nelson and the remaining gang of bank robbers were collectively "Public Enemy Number One".

[5] By the time he met his future wife Helen Wawrzyniak, Nelson was working at a Standard Oil station in his neighborhood which doubled as the headquarters for a group of young tire thieves, known colloquially as "strippers".

Nelson fell into association with the "strippers", and acquainted himself with a number of local criminals, including one who employed him to drive bootleg alcohol throughout the Chicago suburbs.

Aided by his contacts within the Touhy Gang, Nelson fled west to Reno, where he was harbored by William Graham, a known crime boss and gambler.

During his San Francisco Bay area criminal ventures, Nelson met John Paul Chase and Fatso Negri, who later became close associates.

[9] In Reno the next winter, Nelson first met the vacationing Alvin Karpis, who in turn introduced him to Midwestern bank robber Eddie Bentz.

Nelson and his wife traveled west to the San Francisco Bay Area, where he recruited John Paul Chase and Fatso Negri for a new wave of bank robberies the following spring.

Although the details remain in some dispute, the escape is suspected to have been arranged and financed by members of Nelson's newly formed gang, including Homer Van Meter, Tommy Carroll, Eddie Green, and John "Red" Hamilton, with the understanding that Dillinger would repay some part of the bribe money out of his share of the first robbery.

The night Dillinger arrived in the Twin Cities, Nelson and his friend John Paul Chase were cut off by another car driven by local paint salesman Theodore Kidder.

[15] Two days after this, the new gang (with Hamilton's participation as the sixth man uncertain) struck the Security National Bank at Sioux Falls, South Dakota.

In the robbery, which netted around $49,000 (figures differ slightly), Nelson severely wounded motorcycle policeman Hale Keith with a burst of sub-machine-gun fire as the officer was arriving at the scene.

[20] In the aftermath of the Mason City robbery, Nelson and John Paul Chase fled west to Reno, where their old bosses Bill Graham and Jim McKay were fighting a federal mail fraud case.

According to Bryan Burrough's book Public Enemies: America's Greatest Crime Wave and the Birth of the FBI, 1933–34, this most likely happened when Wanatka was playing cards with Dillinger, Nelson, and Hamilton.

[citation needed] Melvin Purvis and a number of agents arrived by plane from Chicago, and with the gang's departure imminent, attacked the lodge quickly and with little preparation, and without notifying or obtaining help from local authorities.

Wanatka offered a one-dollar dinner special on Sunday nights, and the last of a crowd estimated at 75 people were leaving as the agents arrived in the front driveway.

Dillinger, Van Meter, Hamilton, and Carroll escaped through the back of the lodge, which was unguarded, and made their way north on foot through woods and past a lake to commandeer a car and a driver at a resort a mile away.

Shortly after Nelson had entered the home, taking the Koerners hostage, Emil Wanatka arrived with his brother-in-law George LaPorte and a lodge employee (while a fourth man remained in the car) and were also taken prisoner.

As they were preparing to leave, with Wanatka driving at gunpoint, another car arrived with two federal agents – W. Carter Baum and Jay Newman – as well as a local constable, Carl Christensen.

Back on foot, he wandered into the woods and took up residence with a Chippewa family in their secluded cabin for several days before making his final escape in another commandeered vehicle.

[26] A day after the Little Bohemia raid, Dillinger, Hamilton, and Van Meter ran through a police roadblock near Hastings, Minnesota, drawing fire from officers there.

[27][28] Hamilton reportedly died in hiding on April 30 or May 1, 1934, and was secretly buried by Dillinger and others, including Nelson, who had rejoined the gang in Aurora, Illinois.

[31] On the morning of June 30, Nelson, Dillinger, Van Meter, and one or more additional accomplices robbed the Merchants National Bank in South Bend, Indiana.

One man involved in the robbery is believed to have been Pretty Boy Floyd, based on several eyewitness identifications as well as the later account of Joseph "Fatso" Negri, an old Nelson associate from California who was serving as a gofer for the gang at this time.

When the meeting was interrupted by two Illinois state troopers, Fred McAllister and Gilbert Cross, Nelson fired on their vehicle with his converted "machine gun pistol", wounding both men as the gangsters retreated.

[37] On August 23, Van Meter was ambushed and killed by police in St. Paul, Minnesota, leaving Nelson as the sole survivor of the so-called "Second Dillinger Gang".

In the ensuing months, Nelson and his wife, usually accompanied by Chase, drifted west to cities including Sacramento and San Francisco, California and Reno and Las Vegas, Nevada.

They often stayed in auto camps, including Walley's Hot Springs, outside Genoa, Nevada, where they hid out from October 1[38] before returning to Chicago around November 1.

[43][44] On the morning of November 27, Nelson, along with his wife Helen Gillis and associate John Paul Chase, headed south in a stolen V8 Ford towards Chicago on U.S. Highway 12 (now US-14).

Nelson was shot a total of nine times; a single (and ultimately fatal) machine gun slug had struck his abdomen and eight of Hollis's shotgun pellets had hit his legs.

At a different hospital, Cowley lived for long enough to confer briefly with Melvin Purvis and have surgery, before succumbing to a stomach wound similar to Nelson's.