You probably know a little about the notorious Wild West outlaw known as Billy the Kid, who was born Henry McCarty in 1859 but often went by the alias William Bonney. You may have studied him in a history class and/or became introduced to his exploits in the Young Guns movies from the 1980s.

If you aren’t familiar with Billy the Kid, here is a brief rundown.

Billy came to fame during the 1880s, when he was a major player in a range war in New Mexico Territory. After killing at least three men, he was captured and put in jail, then killed two deputies during an escape. According to historical record, Billy went on the lam for a couple of months. He was then shot and killed by Sheriff Pat Garrett in Fort Sumner, New Mexico, which is where his grave is located. . . supposedly.

Not long after the reported shooting of Billy the Kid, conspiracy theories began to circulate that his death was an elaborate hoax. The theory, which is not improbable, states that Garrett and Billy staged the death, as the two men were actually friends. Afterwards, they split the reward money and Billy left the area to live out his life under a different identity.

The reality is that, in 1881, it wouldn’t have been too difficult to create such a hoax. As a sheriff, Garrett had the authority to sign off on any death certificate, and he had the power to keep inquisitive people away from the body. It is curious that there are no known photographs of Billy the Kid’s body, which is a bit strange considering that it was common to photograph the corpses of known criminals at the time.

One of the first men who was suspected to be Billy the Kid was an Arizonan named John Miller. The first public record of Miller is an August 8, 1881 marriage certificate, which was just three weeks after Billy was killed by Garrett. He married a Mexican woman and moved to Arizona where he became a successful rancher. Interestingly, Miller never claimed to be Billy the Kid; some of his family members came forward in the 1930s with the claim.

Miller was said to have had permanent injuries from a gunshot wound, and he definitely had some physical similarities to Billy the Kid.

But the claimant to Billy the Kid’s identity who received the most attention was Brushy Bill Roberts.

Roberts was a wily old Texas ranch hand who was fond of tall tales when he entered the scene in 1948. During that year, a Texas lawyer located an elderly man who claimed to be a veteran of the Lincoln County, New Mexico Range War and who asserted that Billy the Kid was still alive and living in Texas.

Brushy Bill was located and, sure enough, he claimed to be Billy the Kid. He even requested a pardon from the governor of New Mexico for his crimes, but he was denied. Brushy Bill died in 1951 and was quickly forgotten about until he was used as a character in the Young Guns movies. The movies led to more interest and the case was then profiled on an episode of Unsolved Mysteries. Due to the limits of science at the time, however, there was little that anyone could do to prove or disprove the story.

Finally, as DNA testing became more common and affordable in the 2000s, a DNA sample was taken from Miller’s exhumed body. It was then compared to blood drops taken from the wooden floor of the Lincoln County jail that were believed to have come from Billy the Kid. Unfortunately, the sample from the jail was too degraded to make a match.

Investigators next planned to exhume Billy’s mother and Brushy Bill, but neither have been exhumed as of the writing of this book.

Perhaps this will be one mystery that will forever remain unsolved—a fascinating chapter belonging to the legend and lore of America’s frontier history.