Friday, August 17, 1877; George Atkins's Saloon, Fort (Camp) Grant, Arizona Territory---Billy "the Kid" Bonney (known at this time as Henry Antrim, Kid Antrim, and Austin Antrim) rides into Fort Grant and goes to the Atkins saloon on this day probably hoping to simply do some gambling in the saloon of George Atkins and increase the money in his pockets. Gus Gildea, a local cowboy who is present in the saloon, will later say Billy "came to town dressed like a country jake, with store pants on and shoes instead of boots, with a six-gun stuck in his trousers." Shortly after sitting down to a card game, he gets into an argument with the local blacksmith, a large, hulking man known as Frank P. "Windy" Cahill. Cahill is known to be a bully to many, most notably to the Kid, whom he often has beaten up and humiliated at the Fort. When the Kid had been arrested a short time previously at the Fort, it was Cahill who attached shackles to him. And although Billy had been bested by Cahill several times before, he isn't going to be on this night.
Cahill starts the argument by calling the Kid a "pimp." Billy quickly responds by calling Cahill a "sonofabitch." The comment setting off the bullying blacksmith, he attacks Billy, knocks him to the ground, pins him to the ground with his knees, and begins to punch him. The Kid struggles to get free, but it's no use. Billy is only 5'7" or so, and weighs probably no more than 135lbs., whereas Cahill is over 6' and weighs over 200 lbs. Hardly a fair fight. When Billy realizes the futility of his situation, he reaches for his pistol, and somehow manages to get it free. He shoves the end of the barrel into Cahill's gut. Cahill jerks and straightens up, but makes no attempt to get off the Kid. Billy's only reply to this is a bullet exiting from his pistol and entering Cahill's gut. Cahill topples off of Billy, and Billy jumps to his feet. Instantly running out of the saloon, he jumps on the back of a horse tethered outside, and gallopes away.
Cahill is taken to the Fort's post hospital, but it is clear his wound will be fatal. The next day, the local notary public, who is also the local justice of the peace, Miles L. Wood, arrives at Cahill's bed and takes a statement from him, which reads: "I, Frank Cahill, being convinced that I am about to die, do make the following as my final statement. My name is Frank P. Cahill. I was born in the county and town of Galway, Ireland; yesterday, Aug. 17, 1877, I had some trouble with Henry Antrem [sic], otherwise known as Kid, during which he shot me. I had called him a pimp and he called me a s---- of a b----; we then took hold of each other; I did not hit him, I think; saw him go for his pistol and tried to get hold of it, but could not and he shot me in the belly; I have a sister named Margaret Flannigan living in East Cambridge, Mass., and another named Kate Conden, living in San Francisco." Only a short time later, Cahill dies. Later in the day, a coroner's inquest is held, and the killing is ruled "criminal and unjustifiable, and that Henry Antrim alias Kid is guilty thereof." The Kid, however, will never be arrested for the killing. Before anyone even has the chance to arrest him, he'll be out of Arizona and in New Mexico, never to return.