Additional charges have now been laid following a crash in Chatham-Kent earlier this year.
In late April, officers were called to a collision involving a Dodge Ram on Middle Line between Charing Cross Road and Erieau Road.
Police were told by witnesses that the occupants of the truck then transferred alcohol to a minivan before they were picked up by another vehicle.
Officers found a 36-year old Chatham man showing signs of impairment and he was arrested, while the minivan was intercepted and a loaded prohibited firearm was discovered.
Two other people, including a 32-year old woman who also showed signs of intoxication, was arrested.
Police say a 39-year old man had an outstanding immigration warrant and was taken into custody.
Investigators have connected the 36-year old suspect to the gun and additional charges were laid on Wednesday.
Charges against all three include: Possession of a Loaded Prohibited Firearm, Possession of a Firearm Knowing its Possession is Unauthorized, Tampering with Serial Number of a Firearm and Possession of a Prohibited Firearm with Ammunition.