EL PASO, Texas (Border Report) – A federal grand jury has charged four men in connection with an alleged conspiracy to drive dozens of migrants in a locked trailer several hundred miles to Houston.

Wednesday’s charges stem from an investigation started last month after authorities in Eagle Pass, Texas, received reports of vehicles converging around a semi-truck trailer parked in a business lot.

Border Patrol agents were first on the scene and watched as a green Chevrolet Tahoe dropped off passengers who went on to get inside the trailer, according to a criminal complaint filed April 5 in U.S. District Court for the Western District of Texas.

The green Tahoe returned less than half an hour later to drop off more people. Homeland Security Investigations agents, Texas Department of Public Safety troopers and Maverick County Sheriff’s deputies mobilized and arrived in time to see multiple individuals take cover underneath the trailer and some trying to get into a hidden compartment, according to the complaint.

A Nissan Altima parked next to the trailer took off at high speed and was chased down by DPS troopers. A driver identified as Jesus Angel Martinez was taken into custody. Records show that Maverick County deputies tracked down the green Tahoe separately and arrested driver Francisco Javier Vasquez without incident.

Authorities took the drivers and 27 migrants found in or near the trailer to a U.S. Border Patrol station for investigation. Border agents remained on the scene and later watched a white Toyota Corolla approach the trailer, with one of the occupants getting down to approach the vehicle. The Toyota left and agents followed it to the local Motel 6.

Records show border agents watching the Motel 6 saw the individuals come out two hours later, board the Toyota and begin to drive away. A Maverick County deputy stopped the vehicle for a traffic infraction; HSI agents arrived, talked to the occupants and took them to the Border Patrol station.

The criminal complaint alleges that the two men identified as Joshua Dorsh and Troy Allen Slaughter volunteered to tell investigators that they would be paid $10,000 to transport migrants in the trailer from Eagle Pass to Houston. Both men said this would have been their third time transporting unauthorized foreign nationals in trailers to Houston, according to the complaint. The documents don’t identify the person or party paying the men.

Vasquez and Martinez allegedly said they would be paid between $1,500 and $3,000 just for ferrying migrants from various locations to the parked trailer, the complaint alleges.

Wednesday’s indictment charges Dorsh, Slaughter, Martinez and Vasquez with one count of conspiracy to transport illegal aliens and one count of transportation of illegal aliens while placing lives in jeopardy. The latter refers to transporting the migrants in a locked trailer box over long distances, a practice that has led to multiple migrant deaths .