Ryan Louis Mosqueda, a 27-year-old gunman, opened fire at a US Border Patrol building before being killed. He was reported missing from Weslaco, Texas. The gunman, who was killed after opening fire at a US Border Patrol building and its agents, was identified as Ryan Louis Mosqueda. He was 27-year-old and was reported missing from a location in Weslaco, Texas, at around 4 am.