SAN ANTONIO — Another person has pleaded guilty for their involvement in the deadliest human-smuggling event in U.S. history, which killed 53 migrants in a tractor-trailer.  

Riley Covarrubias-Ponce, 31, was a member of a human smuggling organization that was responsible for illegally transporting 66 adults and children from multiple Central American countries into the United States, according to court documents. 

Covarrubias-Ponce, a Mexican national, helped coordinate with other members of the group the transportation of migrants in a tractor-trailer from Laredo to San Antonio, where most of the migrants were found dead on June 27, 2022, due to poor ventilation in the sweltering, triple-digit heat. 

“Covarrubias-Ponce pleaded guilty to one count of conspiracy to transport illegal aliens resulting in death; one count of conspiracy to transport aliens resulting in serious bodily injury and placing lives in jeopardy; one count of transportation of illegal aliens resulting in death; and one count of transportation of illegal aliens resulting in serious bodily injury and placing lives in jeopardy,” according to the United States Attorney’s Office in the Western District of Texas. 

The maximum sentence he could face is life in prison. 

Back in September, Christian Martinez, 29, pleaded guilty to similar charges for his role in the deadly smuggling attempt. Martinez, who lived in suburban Houston, took the driver of the trailer to San Antonio to pick up the vehicle and continued to exchange messages with the group tracking its progress. 

Juan Francisco D’Luna Bilbao also pleaded guilty to the same charges as Covarrubias-Ponce and Martinez as well as a firearms charge back in June 2023. 

The four other defendants’ cases are still pending, which includes the driver of the tractor-trailer.