Four people (defendants), including three adult males and a sixteen-year-old female (Jane Doe), were arrested during a traffic stop after police found two loaded handguns, a machine gun and heroin in the vehicle in which they were driving. Police found the handguns in an open purse lying on the seat or the floor near Jane Doe. The purse, which Jane Doe acknowledged belonged to her, would not close due to the size of the handguns. Police then pried open the trunk and found the machine gun and heroin. At trial, the court admitted all of the weapons and the drugs into evidence, relying on New York Penal Law §265.15(3), which states that the presence of a weapon in a vehicle is presumptive evidence that all passengers of the vehicle had unlawful possession of the weapon, unless certain exceptions apply, including if the weapon is found on the person of one of the occupants. The three male occupants of the vehicle asserted that this exception should apply because the handguns were found in Jane Doe’s purse. The judge instructed the jury that it may rely on the presumption in New York Penal Law §265.15(3) unless there is evidence contradictory to that conclusion. The judge also explained that constructive possession of the weapon requires the intent and ability to exercise dominion over the weapon and that the mandatory presumption of innocence prevails unless the jury is convinced beyond a reasonable doubt that the occupants of the vehicle possessed the handguns. All four occupants were acquitted of possessing the machine gun and drugs found in the trunk, but were convicted of possessing the handguns. After unsuccessfully seeking post-conviction relief in the state courts, the occupants sought habeas corpus relief in federal district court. The district court granted habeas relief because it found that the presence of the guns in Jane Doe’s purse was insufficient to convict the other passengers and the Second Circuit affirmed, finding New York Penal Law §265.15(3) unconstitutional on its face. The government appealed to the United States Supreme Court.