In Huddleston v. United States (1987), the U.S. Supreme Court ruled that evidence of a defendant's prior or similar acts could be admitted in court under Federal Rule of Evidence 404(b) without requiring proof beyond reasonable doubt that these acts occurred, as long as they are relevant to an issue at trial such as intent or knowledge. The case involved William Earl Huddleston who was charged with selling stolen goods across state lines and challenged the admission of evidence regarding his previous dealings in stolen merchandise. He argued this violated his rights because it suggested a criminal disposition on his part, potentially biasing the jury against him. However, the Supreme Court upheld its admissibility stating that safeguards existed within other rules of evidence and instructions given by judges to juries about how such information should be considered.

In the dissenting opinion for Huddleston v. United States, Justice Thurgood Marshall argued that the majority's decision failed to adequately protect defendants' rights. He contended that allowing evidence of a defendant's past crimes into trial without first determining its relevance and potential prejudice could unfairly sway jurors against the defendant. This, he believed, violated their right to a fair trial as guaranteed by the Sixth Amendment. Furthermore, he criticized the majority’s reliance on Rule 404(b) of Federal Rules of Evidence which permits such evidence if it is relevant to proving something other than character or propensity towards crime - arguing this was too broad an interpretation and left room for misuse by prosecutors seeking conviction rather than justice.