In Hampton v. United States, the Supreme Court upheld a conviction for selling heroin to federal agents. The defendant argued that he was entrapped because the drugs were supplied by a government informant and therefore, his due process rights were violated. However, the court ruled 5-4 in favor of the government stating that if a defendant is predisposed to commit an illegal act, it does not matter whether or not the government supplies him with contraband as part of its investigation. This decision expanded upon previous rulings on entrapment and clarified that even when law enforcement provides materials necessary for committing an offense; this does not constitute entrapment if there's evidence showing predisposition on behalf of accused towards criminal conduct.

In the dissenting opinion for Hampton v. United States, Justice Brennan argued that the majority's decision to uphold Hampton's conviction despite evidence of government entrapment was a dangerous precedent. He contended that it allowed law enforcement agencies to manufacture crimes and then prosecute individuals for participating in them, which he believed undermined the integrity of both criminal justice system and individual rights. Justice Brennan also criticized the majority’s reliance on previous cases where defendants had been predisposed to commit crimes before being entrapped by government agents; in this case, there was no such predisposition evident. Furthermore, he expressed concern about potential abuses of power by law enforcement if they were given free rein to create illegal scenarios without any legal repercussions or limits on their actions.