In Jackson v. Denno, the U.S. Supreme Court ruled that a defendant has the right to have a court determine whether his confession was voluntary before it can be admitted as evidence in trial. The case involved New York resident Daniel Thomas Jackson who had been convicted of first-degree murder based on an allegedly coerced confession obtained while he was in police custody without legal representation present. He appealed his conviction arguing that his constitutional rights were violated because he did not receive a fair hearing on the voluntariness of his confession prior to its admission at trial. The Supreme Court agreed with Jackson and held that New York's procedure for evaluating confessions, which allowed juries to assess their voluntariness even after they had heard potentially prejudicial details contained within them, violated due process under Fourteenth Amendment protections against self-incrimination and guaranteed right to counsel during interrogations. This landmark decision established what is now known as "Jackson-Denno" hearings where judges must independently evaluate the circumstances surrounding any given confession before determining its admissibility at trial.

In the dissenting opinion for Jackson v. Denno, Justice Clark argued that the majority's decision to require a separate hearing on the voluntariness of confessions before they can be admitted into evidence was unnecessary and could lead to confusion. He contended that juries are capable of determining whether or not a confession is voluntary based on instructions from judges about what factors to consider. Furthermore, he expressed concern that this new rule would result in more appeals and retrials due to errors made during these separate hearings. Justice Clark also disagreed with the majority's interpretation of previous case law, arguing that it did not support their conclusion.