Francis Augustus Hamer (March 17, 1884 – July 10, 1955) was an American lawman and Texas Ranger who led the 1934 posse that tracked down and killed criminals Bonnie Parker and Clyde Barrow.

Although his formal education ended after the sixth grade, as a youth Hamer displayed several unusual abilities, including an extremely high level of intelligence and a near eidetic memory.

In 1908, he resigned from the Rangers to become the City Marshal of Navasota, Texas, a lawless boom-town wracked by violence; "shootouts on the main street were so frequent that in two years at least a hundred men died.

[6] In 1911, he moved to Houston to work as a special investigator for Mayor Horace Baldwin Rice, where he was seconded to the Sheriff's Office of Harris County.

Hamer rejoined the Rangers in 1915 and was assigned to patrol the South Texas border around Brownsville during the Bandit War and La Matanza.

He participated in numerous raids and shootouts, and he was involved in a gun battle with smugglers on March 21 which resulted in the death of Prohibition Agent Ernest W.

In 1918, Hamer physically threatened State Representative José Tomás Canales, who was leading an investigation into Texas Rangers accused of abusing residents of the Rio Grande Valley.

Hamer and a handful of Rangers were charged with protecting the trial of a black rape suspect, George Hughes, in the town of Sherman.

Hamer wrote a detailed exposé of the racket, which he termed "the bankers' murder machine", and he took his article to the press room of the State Capitol and handed out copies.

[19] In the early 1930s, Clyde Barrow and Bonnie Parker's crime spree generated vast media coverage which embarrassed law enforcement and government officials in a half dozen states.

On January 16, 1934, Barrow, Parker, and associate Jimmy Mullens raided Eastham prison farm, freeing Raymond Hamilton, Henry Methvin, Hilton Bybee, and Joe Palmer.

Historian John Neal Phillips says that "paying back" the Department of Corrections for abuse that Barrow had received while imprisoned motivated many of his actions and underlay his crime spree.

He died in the hospital on January 27 soon after Texas prison administrator Lee Simmons assured him that he would send his killer Joe Palmer to the electric chair.

Hamer was commissioned as an officer of the Texas Highway Patrol, then seconded to the prison system as a special investigator charged with apprehending Barrow and his colleagues.

"[24] In the next couple of months, Barrow, Parker, and Henry Methvin robbed banks in Lancaster, Texas, Poteau, Oklahoma, and the Iowa towns of Rembrandt, Knierim, Stuart, and Everly.

An eyewitness account gained widespread newspaper coverage, stating that a drunken Bonnie had emptied her gun into the prone body of Patrolman Murphy at Grapevine, laughing as she fired at the way that his "head bounced like a rubber ball" on the road.

[29] The lurid newspaper stories and the furor which they created increased the pressure on government and law enforcement to capture the criminals, and Governor Ferguson placed a $500 bounty on Bonnie for her alleged role in the murder of Patrolman Murphy.

[30] Five days later, popular opinion turned against the criminals even more when Barrow and Methvin killed Constable Calvin Campbell, a 60-year-old single father, near Commerce, Oklahoma.

[31] In mid-March, Henry Methvin's family contacted Bienville Parish Sheriff Henderson Jordan about their son, his legal troubles, and his involvement with Barrow.

They examined Barrow's abandoned V-8 Ford at Sowers and discovered that the bullets from his Thompson submachine gun had not penetrated its body, so this time Hinton requested a Browning automatic rifle.

Barrow stopped his car at the ambush spot and the posse's 150-round fusillade was so thunderous that people for miles around thought a logging crew had used dynamite to fell a huge tree.

All six, however, agreed that Deputy Oakley stood and fired the opening shot from his Remington Model 8, and that his bullet hit Barrow's left temple and killed the outlaw instantly.

[36] Hamer used a customized .35 Remington Model 8 semiautomatic rifle with a 15-round magazine that he ordered from Pet McKay's Sporting Goods store in Austin, Texas.

At the outbreak of war in Europe in 1939, he and 49 other retired Texas Rangers offered their services to King George VI to help protect the United Kingdom in case of Nazi invasion.

[17] In September 1948, Hamer was called back to Ranger duty to play a small role in the notorious 1948 United States Senate election in Texas.

[47] Kevin Costner portrays Hamer in the 2019 Netflix original film The Highwaymen, which was released to theaters for a short run and began streaming in March 2019.