Before he started using the alias "William Bonney", McCarty's first arrest was for stealing food in late 1875. Within five months he was arrested for stealing clothing and firearms. Two days later, he escaped from jail and fled from New Mexico Territory into the neighboring Arizona Territory, making him an outlaw and a federal fugitive. After murdering a blacksmith during an argument in August 1877, Bonney became a wanted man in Arizona Territory. He returned to New Mexico and joined a group of cattle rustlers. He became a well-known figure in the region when he joined the Regulators and took part in the Lincoln County War. In April 1878, the Regulators killed three men, including Lincoln County Sheriff William J. Brady and one of his deputies. Bonney and two other Regulators were later charged with killing all three men.