"The vehicle ran off the road and caught gravel and then tried to recorrect and then caused the vehicle to turn over several times".
"The Border Patrol was pursuing a vehicle and one of my deputies assisted in the pursuit, and took over the pursuit just west of Big Wells", Mr. Boyd told KSAT-12. "He was able to get him out of the vehicle and the driver was actually walking", Boyd said.
Four victims were dead at the scene, according to the Texas Department of Public Safety.
Most of the occupants in the SUV were believed in the country without legal permission.
The Border Patrol said in a statement Sunday night that two other vehicles had been travelling alongside the SUV earlier in the day. The driver, believed to be a United States citizen, was rushed to a hospital; the passenger, also believed to be a USA citizen, now is in custody.
When asked why Border Patrol agents started the chase, Boyd said, "It's called good police work". One person died upon arriving at the hospital, he said.
Border Patrol officials have repeatedly warned of the dangers of smuggling large numbers of people in vehicles.
"This, I think, is a flawless example, of why are borders need to be secured", Boyd said.
He added: 'This is a flawless example of why our borders need to be secure'. "The deputy actually took him into custody".
Twelve people were ejected from the vehicle.
Yolanda Choates, a US Customs and Border Protection spokeswoman, directed questions to the Dimmit County Sheriff's Office.