St. Leon was eventually dismissed from the force due to his drinking however he did remain in contact with John Hughes and worked with him in an unofficial capacity for a time.

[1] In 1889, hired by the Fronteriza Mining Company, he was involved in the capture of a group of silver ore thieves who were traveling with a large mule caravan en route to their hideout where they planned to hide the loot in an abandoned silver mine outside Shafter, Texas.

Posing as one of the escorts, he led the robbers into an ambush as Texas Rangers John R. Hughes and Lon Oden, assisted by St. Leon, attempted to take them into custody.

[2] While living among the Mexican-American peasants along the border, he was able to obtain a list of twenty names of men involved in the murder of Captain Frank Jones who had been killed while attempting to arrest Jesus and Severino Olguin, members of a local bandit gang of thieves and murders in the El Paso-area.

St. Leon had called on Dr. Breaux to assist him in arresting Collier and Finley, who were recklessly discharging their firearms, with both men being wanted on charges of horse theft also.