The United States government (plaintiff) prosecuted Julio De La Torre (defendant) on two counts of possessing a controlled substance with intent to distribute, one count for methamphetamines and the other for marijuana. The trial evidence established that police raided a hotel room where De La Torre and others had been smoking marijuana. A police officer saw De La Torre running from the hotel with a backpack, which the officer later saw De La Torre discard. When police retrieved and searched the backpack, they found distribution quantities of marijuana and methamphetamines inside. De La Torre testified that another occupant of the room gave him the backpack, and that because the room's occupants had been using marijuana exclusively, De La Torre believed the backpack contained marijuana but no other drugs. De La Torre admitted that, after police retrieved and searched the backpack, he realized that the backpack also contained methamphetamines. The judge instructed the jury that the government did not need to prove that De La Torre knew the precise nature of the illegal drugs in his possession, and that the jury could convict De La Torre on the methamphetamines count even if they believed that De La Torre was ignorant of the methamphetamines in the backpack. The jury convicted De La Torre for possessing both marijuana and methamphetamines, and De La Torre appealed the methamphetamines conviction to the United States Court of Appeals for the Tenth Circuit.