Patrol Inspector Lon Parker was killed in a battle with alien liquor smugglers 2 1/2 miles south of Wills Ranch, west of the Huachuca Mountains, in Arizona, on July 25, 1926. Late that afternoon he left camp alone to take up the trail of mounted liquor smugglers. Tracks of a man and a horse had been discovered with evidence that the man had ridden the horse where the terrain was smooth and walked over rough places, indicating that the horse was loaded with liquor or other contraband. Nothing was heard from Inspector Parker until the Wills family returned to their ranch at about 6 p.m. the same day, and found him on their woodpile dying from a gunshot wound. He had been shot with a rifle bullet in the back. He died within a few minutes without regaining consciousness.
During the investigation, the body of a Mexican was found about 2 1/2 miles from the Wills' home. The Mexican was identified as Artilio Espinosa, a well-known smuggler. Espinosa's horse, with 20 gallons of mescal in cans strapped on his back, was found dead of a bullet wound. From the tracks in the area and the position of Espinosa and his horse, the investigating officers theorized that Espinosa was accompanied by another smuggler, that Officer Parker rode up to Espinosa, covered him with a pistol and was shot by Espinosa's companion, who was purposely riding at some distance for the purpose of protecting Espinosa and the liquor, and that Inspector Parker, although mortally wounded, retained sufficient command of himself to kill Espinosa and his horse, using only one shot for each, and then rode 2 1/2 miles to Wills Ranch, where he collapsed.