A photograph has emerged of what is believed to be the only image of Billy the Kid and his killer Pat Garrett together - and could be worth millions.
The pair were once friends who gambled and drank together in Lincoln County, New Mexico. However, when Garrett was made sheriff the friendship ended and one of the most famous feuds of the American Old West began.
The photograph was bought for just US$10 ($14.5) at a flea market in 2011 and was hanging for years in a North Carolina home - in a guest room that is rented out on Airbnb.
After watching a documentary in 2015 about the discovery of another photo of the Kid playing croquet, Frank Abrams, a lawyer with a keen interest in history, took another look at the photograph that he had assumed was a group of cowboys from the American South.
He carefully studied the tintype image, which is a photograph produced on a thin sheet of metal, comparing it to other pictures of the Kid and Garrett.
Abrams eventually became convinced the character on the far right in a dark hat was Garrett and the man with the prominent Adam's apple, second from the left, could be the Kid.
He consulted Robert Stahl, an expert on the Kidd and William Dunniway, a tintype specialist, who said the photograph was probably taken between 1875 and 1880.
"Everything matches: the plate, the clothing, the firearm," William Dunniway, a tintype expert, told the New York Times.
Dunniway worked with Kent Gibson, a forensics expert, on the picture. Along with help from facial recognition technology and a hand-writing expert, they concluded it was indeed of the two friends-turned-enemies.
It could be a very significant find. Not only did the croquet picture of the Kid sell for $5 million in 2015, only two pictures of the Kid were previously known to exist. This could also be the only picture of the outlaw and lawman together.
"This is completely unknown, that Garrett and Billy are in a picture together," said Abrams. "This is amazing, everybody is excited."
"If I had known it was one of the most famous photos in history, I would have charged more for the room!" he joked - adding that the image was now in a safe deposit box.
The Kid, who was born Henry McCarty and also went by the name William H. Bonney, and Garrett had been friends until the latter was elected Lincoln County Sheriff in November 1880. He immediately warned the notorious outlaw to leave town.
"Garrett was saying, 'If you leave New Mexico, I'm not going to pursue you. But if you stay in the territory, then no matter where you are, I have to come after you,'" Mr Stahl explained.
The Kid remained and Garrett was true to his word and arrested his former friend. However, the Kid later escaped, shooting dead two deputies and riding out of town on a horse - according to legend, singing as he went.
His freedom was to be short-lived. The sheriff tracked down the Kid once again, finally shooting him dead at Fort Sumner in July 1881.