The U.S. Constitution's Equal Protection principles demand that a prosecutor's "decision whether to prosecute may not be based on an unjustifiable standard such as race, religion, or other arbitrary classification." If a prosecutor prosecutes a defendant based on such arbitrary classifications, the defendant may raise the selective prosecution defense under the Equal Protection principles of the U.S. Constitution. The U.S. Supreme Court first recognized the validity of the selective prosecution defense over one hundred years ago. Since that time, the Court has continuously narrowed the defense's application. As a result, the standard for proving the elements of a selective prosecution defense is now "a demanding one." Defendants seeking discovery to help prove the validity of their selective prosecution defenses also face a "correspondingly rigorous" discovery standard.

In 2006 the Fourth Circuit determined whether the U.S. District Court for the Eastern District of Virginia erred when it denied three Islamic defendants' discovery request for their selective prosecution defense. The district court convicted the defendants of various crimes relating to their ties to an Islamic terrorist organization. The defendants claimed that the Government failed to prosecute non-Muslim individuals in the United States who engaged in similar criminal conduct. Furthermore, the defendants claimed that the Government prosecuted them because they were Muslims in a post-9/11 world. The Fourth Circuit affirmed the district court's decision to deny the defendants' discovery request.