The federal government (plaintiff) prosecuted Juvenal Ambriz (defendant) for distribution of a controlled substance, in violation of 21 U.S.C. § 841(a)(1). The trial evidence established that a federal agent working undercover at a club purchased drugs from a club customer. When the customer left the club, the agent provided his description to police officers, who stopped the customer's car. The driver matched the customer's description, and his driver's license identified him as Ambriz. The officers arrested Ambriz after a search of his car turned up a quantity of baggies similar to those that the agent bought at the club. The trial judge denied Ambriz's request for a jury instruction that simple possession of a controlled substance, in violation of 21 U.S.C. § 844(a), is a lesser-included offense of § 841(a)(1) distribution. The jury convicted Ambriz on the distribution charge, and Ambriz appealed to the Fifth Circuit Court of Appeals.