Leonzo Mateo was 17 when he crossed the border on foot with a group around July 20, 2012, and was last seen in the San Luis Mountains of Pima County, Arizona. He is described as Hispanic, between 5 feet 4 inches and 5 feet 6 inches, about 120 to 140 pounds, with short black hair, very dark brown eyes, and a small scar under his right eye about 3/8 inches long.

Around July 23 or 24 Leonzo reportedly became ill and had a nosebleed; members of the party left him to rest beside a tree and later were found by Border Patrol, but Leonzo was not with them. The Pima County Medical Examiner’s Office is noted as having taken on his case and the investigation remains open.

Anyone who was in that area or who may have been with the traveling party around July 20–24, 2012, and has information about Leonzo Mateo is asked to come forward.