He was pursued and killed by a group of Bureau of Investigation (BOI, later renamed FBI) agents led by Melvin Purvis.

He committed a series of bank robberies over the next several years, and it was during this period that he acquired the nickname "Pretty Boy," although accounts differ.

In one account Orville Drake gave him the name because he would wear a white button-up dress shirt and slacks to work in the oil fields.

In another account, the payroll master in the 1925 St. Louis Kroger office holdup described one of the robbers as "a pretty boy with apple cheeks".

On March 9, he was arrested in Kansas City on investigation, and again on May 7 for vagrancy and suspicion of highway robbery, but he was released the next day.

[6] Floyd was a suspect in the deaths of Kansas City brothers Wally and Boll Ash, who were rum-runners found dead in a burning car on March 25, 1931.

In November, three members of Floyd's gang attempted to rob the Farmers and Merchants Bank in Boley, Oklahoma.

[13] Floyd and Adam Richetti became the primary suspects in a gunfight known as the "Kansas City massacre" on June 17, 1933, which resulted in the deaths of four law enforcement officers.

The gunfight was an attack by Vernon Miller and accomplices on lawmen escorting robber Frank "Jelly" Nash to a car parked at the Union Station in Kansas City, Missouri.

Kansas City detectives William Grooms[15] and Frank Hermanson,[16] Oklahoma police chief Otto Reed,[17] and special agent Ray Caffrey[18] were killed.

Two other Kansas City police officers survived by slumping forward in the back seat and feigning death.

Evidence against them included their presence in Kansas City at the time, eyewitness identifications (although these have been contested), Richetti's fingerprint recovered from a beer bottle at Miller's hideout, an underworld account naming Floyd and Richetti as the gunmen, and Hoover's firm advocacy of their guilt.

In addition, a 2002 book on the massacre attributes at least some of the killing to friendly fire by a lawman who was unfamiliar with his weapon, based on ballistic tests.

agents led by Melvin Purvis under the direct supervision of Inspector Samuel P. Cowley[21] shot Floyd on October 22, 1934, in a corn field in East Liverpool, Ohio.

Floyd and Richetti had left Buffalo, New York, on October 18, and their vehicle slid into a telephone pole in heavy fog at 3 am the following morning.

They planned to have the women accompany the tow truck driver into town and have the vehicle repaired while they waited by the roadside.

[23] After dawn on October 19, motorist Joe Fryman and his son-in-law David O'Hanlon passed by, observing two men dressed in suits lying by the roadside.

After enlisting the help of another local police officer, Chester C. Smith (February 14, 1895 – October 23, 1984), who had served as a sniper during World War I, the group of lawmen resumed the pursuit and successfully apprehended Richetti, but Floyd remained on the run.

On October 22, Floyd was able to hitch a ride to East Liverpool, Ohio, where he obtained food at a pool hall owned by his friend Charles Joy.

Differing accounts of the events that followed were given by responding BOI agents, local law enforcement officers, and nearby civilians.

All agree that Floyd was confronted by a group of lawmen soon after leaving the pool hall, and attempted to flee on foot.

[24] BOI accounts state that four of their agents: Hopton, Samuel K. McKee Jr., and David E. Hall, led by Purvis, and four members of the East Liverpool Police Department: Herman H. Roth, Jr., Chester C. Smith, and Glenn G. Montgomery, led by Chief Hugh J. McDermott, were searching the area south of Clarkson, Ohio, in two cars.

"[19] Contradicting this, a news report from the time states that Floyd crawled out of the corn crib toward the Dyke automobile, then changed direction toward a wooded ridge.

[19] Retired East Liverpool police captain Chester Smith described events differently in a 1979 issue of Time magazine.

Purvis questioned Floyd briefly and received curses in reply, so he ordered agent Herman Hollis to "fire into him."

"[26] FBI agent Winfred E. Hopton disputed Smith's claim in a letter to the editors of Time, published in the November 19, 1979, issue.

[29] Floyd's body was embalmed and briefly viewed at the Sturgis Funeral Home in East Liverpool, Ohio, before being sent on to Oklahoma.

[14][failed verification] Several films have been made about Floyd: Pretty Boy, by William Cunnigham, originally published by Vanguard in 1936, was republished by Mongrel Empire Press, Norman, Oklahoma, in 2014.