Border Patrol agents apprehended an armed 29-year-old Tucson man at the Interstate 19 immigration checkpoint near Amado after finding three Mexican nationals hidden in the trunk of his car.

On Wednesday, agents sent the man for a secondary inspection of his Dodge Dart after an agency dog alerted to an odor in the car, according to a news release from Customs and Border Protection.

Agents discovered the illegal immigrants when they opened the vehicle’s trunk. Agents also found a loaded 9 mm pistol in the center console.

Agents arrested the man on suspicion of human smuggling and seized his vehicle and gun.