Tunstall's cowhands and other local citizens form…

Tunstall's cowhands and other local citizens form a group known as the Regulators to avenge his murder, since the territorial criminal justice system is controlled by allies of Murphy, Dolan & Co.

While the Regulators at various times consist of dozens of American and Mexican cowboys, the main dozen or so members are known as the "iron clad", including McCarty, Richard "Dick" Brewer, Frank McNab, Doc Scurlock, Jim French, John Middleton, George Coe, Frank Coe, Jose Chavez y Chavez, Charlie Bowdre, Tom O'Folliard, Fred Waite (a Chickasaw), and Henry Newton Brown.

The Regulators set out to apprehend the sheriff's posse members who had murdered Tunstall.

After the Regulators are deputized by the Lincoln County justice of the peace, together with Constable Martinez, they attempt to serve the legally issued warrants on Tunstall's murderers.

Sheriff Brady arrests and jails Martinez and his deputies in defiance of their deputized status.

They gain release and search for Tunstall's murderers.

They find Buck Morton, Dick Lloyd, and Frank Baker near the Rio Peñasco.

Morton surrenders after a five-mile (eight kilometer) running gunfight on the condition that he and his fellow deputy sheriff, Frank Baker, will be returned alive to Lincoln.

The Regulator captain Dick Brewer assures them they will be taken to Lincoln, but other Regulators insist on killing the prisoners.

William McCloskey, also a friend of Morton, resists such action.

On March 9, 1878, the third day of the journey back to Lincoln, the Regulators kill McCloskey, Morton, and Baker in the Capitan foothills along the Blackwater Creek.

They claim that Morton had murdered McCloskey and tried to escape with Baker, forcing them to kill the two prisoners.

Few believe the story, as they think it unlikely that Morton would have killed his only friend in the group.

As the bodies of Morton and Baker each bear eleven bullet holes, one for each Regulator, Utley believes that the Regulators murdered them and killed McCloskey for opposing them. (Utley, Robert M. (1989) Billy the Kid: A Short and Violent Life, University of Nebraska Press.)

Frederick Nolan writes that Morton took ten bullets, and Baker was shot five times. (Nolan, Frederick (1998). "The West of Billy the Kid". Norman, OK: University of Oklahoma Press.)