A founding member of the Regulators during the Lincoln County War in New Mexico, Scurlock rode alongside such men as Billy the Kid.

Described as 5 feet 8 inches (1.73 m) tall, weighing 150 pounds (68 kg), with brown eyes and dark blond hair, Doc went to Mexico in about 1870.

Scurlock accidentally shot and killed his friend, Mike G. Harkins, manager of John H. Riley's store at Blazer's Mill, while he was examining a pistol on September 2, 1876.

In January 1877, Scurlock and a neighbor, George Coe, were arrested by Sheriff William J. Brady for suspicion of harboring a murdering fugitive and member of the Jesse Evans Gang named Frank Freeman.

On May 14, 1878, he led a posse of 18 to 20 men, which included Billy the Kid, Bowdre, George Coe, Brown, and Scroggins, to the Dolan-Riley cattle ranch, ostensibly in search of those implicated in the killing of MacNab and the wounding of Saunders.

According to Riley, they drove off 26 horses and two mules, killed a herder named Wair; a Navajo Indian employed at the ranch as a cook; and a 15-year-old boy called Johnny.

Writer Robert M. Utley says that they captured a man named "Indian" Manuel Segovia, the likely shooter of McNab, but he was shot while allegedly trying to escape.

The raid by the Regulators resulted in the removal of one of their partisans from a position of authority and his replacement with George Peppin, who was just as strongly attached to the other side.

In the western film, Young Guns, Scurlock was portrayed by actor Kiefer Sutherland, as a polite, moral, poetry writing cowboy.

At the end of the film, Scurlock left Billy the Kid's posse, fleeing from New Mexico with an Asian woman he fell for earlier in the movie in the hopes of starting a new life in the East.

In the sequel, Young Guns II, Scurlock (again played by Sutherland) is serving as a school teacher in New York City when he is arrested and taken back to New Mexico, where he is saved from hanging by The Kid.

He rejoins Billy's posse and is mortally wounded in an ambush led by John W. Poe, played by Viggo Mortensen, when he steps out of their hideout.

In fact, Scurlock was married to a Mexican woman in 1876 and died peacefully in Texas many years after the period of time covered by the movie.

It has been reported that Kiefer Sutherland, faced with scheduling conflicts, refused to return to the Young Guns franchise unless his character died in the movie's "Stinking Springs Shoot Out".