On December 12, 1996, about 4 p.m., Agents Michael W. Barnes, Antonio Guzman, Adolf Tapia, Rolando Gonzalez, David Salinas, Matthew Mizell, and Kevin Brashear, assisted by Del Rio Sector pilot Mike Snyder, were working a trail on the Chittum Ranch in the Carrizo Springs, Texas, area. They spotted a group of about 13 illegal aliens, who ran when the agents approached them. Agents Barnes and Tapia apprehended five of the aliens. Agent Barnes then turned them over to Agent Tapia and began trying to apprehend the remainder of the group. The pilot spotted the remainder running along a creek bottom and was guiding agents toward the area. Agent Barnes was within about 50 yards of them when the pilot stated over the radio that Agent Barnes had gone down. He radioed Agent Barnes, but there was no response. When he notified the other agents in the area of the situation, they started making their way to assist Agent Barnes.
About 4:32 p.m., Agent Tapia found Agent Barnes face down. Agents determined that Agent Barnes was not breathing and had no pulse and immediately started performing CPR. Pilot Snyder radioed for an ambulance and a helicopter. Agent Barnes was placed in a Border Patrol vehicle and transported to the ambulance. About 5:38 p.m., a helicopter took off with Agents Barnes and Guzman for a hospital in San Antonio, arriving at 6:13 p.m. At 6:25 p.m., a doctor advised Agent Guzman that Agent Barnes had died. The medical examiner's office determined he had suffered a massive heart attack.
Agent Barnes was born in San Antonio and grew up in Pearsall, Texas. He served as Supervisory Border Patrol Agent at the Carrizo Springs Border Patrol Station beginning in May 1988 and as Assistant Patrol Agent in Charge at Carrizo Springs beginning in July 1990. In September 1996, he was appointed Patrol Agent in Charge at Carrizo Springs.