(NewsNation) — Five more people have been charged in connection to a human smuggling incident in which 53 migrants were found dead in the back of a semitrailer near San Antonio, Texas, last year, according to a newly unsealed indictment.

A grand jury charged Riley Covarrubias-Ponce, Felipe Orduna-Torres, Luis Alberto Rivera-Leal and Armando Gonzales-Ortega with four federal crimes related to human smuggling, including transportation of illegal aliens resulting in death, per the indictment.

From December 2021 to June 2022, the four suspects allegedly worked together to illegally transport migrants “by sharing routes, guides, stash houses, trucks, trailers, and transporters,” according to federal authorities.

Some of the defendants were allegedly aware the trailer’s air-conditioning didn’t work and would not blow any cool air to the migrants inside, a statement from the Justice Department said.

The four men have been identified as Mexican nationals and have been arrested. If found guilty on the top counts, they each face a maximum penalty of life in prison.

“Today’s arrests demonstrate that those who seek to profit from desperation will be brought to justice,” said Deputy Attorney General Lisa O. Monaco.

A fifth individual remains unnamed and is not yet in custody, according to court documents and a source familiar with the matter.

Two other men, who had already been charged in the case, were also named in the indictment.

The unsealed indictment comes one year after authorities found 67 migrants from Mexico and Central America packed in a sweltering semitrailer. Of those, 53 died from heat and dehydration after the trailer was abandoned near San Antonio.

The tragedy became the deadliest human smuggling incident in U.S. history.

This is a breaking story and will continue to be updated.