A National Guard member deployed to South Texas has been convicted of smuggling illegal aliens into the United States. The conviction, announced on July 21, followed a collaborative investigation by U.S. Immigration and Customs Enforcement Homeland Security Investigations Corpus Christi, the U.S. Department of Defense’s Office of the Inspector General Defense Criminal Investigative Service, and the U.S. Customs and Border Protection Office of Professional Responsibility.
Mario Sandoval, a 27-year-old Houston resident, was found guilty in the U.S. District Court for the Southern District of Texas after a one-day trial. He was charged with conspiring to smuggle illegal aliens.
“Driven exclusively by greed, this individual betrayed the solemn oath he swore to defend when he enlisted in the National Guard,” said HSI Houston Special Agent in Charge Chad Plantz. “His actions directly undermined the very mission he was deployed to support and put his fellow guard members in danger."
Sandoval had been part of Operation Lonestar at the U.S.-Mexico border with the Texas National Guard before beginning his smuggling activities in July 2024 after being released from his orders.
During his trial, evidence included text messages from Sandoval's phone discussing trips from the Rio Grande Valley past immigration checkpoints. Surveillance confirmed his presence at these checkpoints while communicating about law enforcement activity there. Despite defense arguments that no conspiracy existed and that messages were taken out of context, jurors reached a guilty verdict within an hour.
“The conduct in this case represents an unthinkable violation of public trust,” stated U.S. Attorney Nicholas J. Ganjei.
Sandoval was discharged from service in October 2024 and is scheduled for sentencing on October 22, facing up to ten years in federal prison.
Assistant U.S. Attorneys John Lamont and Ashley Martin led the prosecution.
For further updates on HSI Houston's efforts against alien smuggling and related crimes in Southeast Texas, follow them on X at @HSIHouston.
