By 1913 Buffalo Bill Cody employed him in his Wild West show, which toured both nationally and internationally.

On November 21, 1913, Lopez shot and killed a fellow miner named Juan Valdez in Bingham, Utah.

Kerry Boren says that Lopez was exacting revenge for Valdez's alleged murder of the former's brother years before.

Lopez had no intention of surrendering to the authorities and fled across snow-covered mountains on foot to a ranch located near Utah Lake and the present-day town of Saratoga Springs.

As the posse was approaching the ranch house, Lopez opened fire on them from a nearby ditch with a Model 1895 .30-06 Winchester rifle.

At a distance later determined by the Salt Lake Tribune to be 118 yards, Lopez struck the Bingham police chief, John William Grant, in the back and killed him instantly.

A few days later, the police were informed of Lopez's whereabouts and they proceeded to block off the entrances to the mine with armed guards.

The remaining possemen attempted to starve Lopez into submission, but he survived due to the efforts of sympathetic miners, who left food in the tunnels.

Somewhere near the international border, Lopez and his men in 1914 derailed a train, robbed it, and killed nineteen of the twenty American passengers on board.

He was told by an informant that Lopez was expected to attend an upcoming meeting of outlaws near the Rio Grande.

Hamer decided to ambush the meet with some of his men by having them take up positions in an irrigation ditch and fire on the outlaws as they rode across the river border.

After they moved into place, Hamer suspected that the informant had led him into a trap, so he had his men hide the horses and reposition themselves on a low ridge thirty yards away, which overlooked the irrigation ditch.

As the sun began to set, the rangers spotted about twenty armed men approaching on foot to the rear of the ditch.