Ms Rivera, 30, was charged with possession of a firearm after a former felony conviction.
A Guthrie police officer reportedly stopped Stephen Jennings, 41, on June 25, when he noticed the vehicle Jennings was driving had an expired tag.
While Jennings was informing officers he had a gun in the console, police learned the vehicle had been reported stolen.
They were initially stopped after police noticed their vehicle's licence plate had expired, but officers soon noticed the timber rattlesnake in a box on the backseat.
And their discoveries: one bottle of Kentucky Deluxe whiskey and one rattlesnake. Stephen Jennings and Rachel Rivera were pulled over by officers who conducted a search of the vehicle.
After a further search of the auto, police found an open bottle of Kentucky Deluxe whiskey and a container of "yellowish powder" that was labelled "Uranium". Gibbs says the man also admitted to having a gun in the console of the vehicle. "The uranium is the wild card in that situation".
The Guthrie Police Department has not filed charges related to the uranium; officers are still looking into a potential motive.
No charges were laid in connection with the uranium or the rattlesnake.
"Many times it might be unlawful to own a vicious or harmful animal like a rattlesnake, however there are seasons or times where it's authorized to hunt rattlesnakes", Gibbs mentioned, including that Jennings has a valid lifetime fishing and hunting license for the state of Oklahoma permitting him to be in hold of the pet rattlesnake.