One person remains behind and appears to return to the border wall.
The drone appears to follow the truck and trailer as they speed away.
Modlin tweeted that agents eventually stopped the vehicle. They arrested three U.S. citizens on charges relating to human smuggling. Inside the trailer, agents found 20 illegal immigrants, Modlin stated.
A search of the vehicle led to the discovery of a loaded firearm and five grams of methamphetamine, the chief said.
This section of Arizona is served by agents assigned to the Brian A. Terry Border Patrol Station. The station is named in memory of murdered