In Rochin v. California, the U.S. Supreme Court ruled that evidence obtained through physical coercion violated the Due Process Clause of the Fourteenth Amendment and therefore could not be used in a state criminal trial. The case involved Antonio Rochin, who was forcibly made to vomit by police officers after they suspected him of swallowing illegal drugs. The retrieved capsules were then used as evidence to convict him for narcotics possession in a California court. However, upon appeal to the Supreme Court, it was decided that such invasive procedures were so brutal and offensive that they "shocked the conscience," thereby violating Rochin's constitutional rights under due process law - which guarantees fair treatment through normal judicial system especially as a citizen's entitlement.

In the dissenting opinion for Rochin v. California, Justice Felix Frankfurter argued that while the methods used by police to obtain evidence were undeniably brutal and offensive, it was not within the Supreme Court's jurisdiction to determine whether they violated due process of law. He contended that such decisions should be left up to individual states unless there is a clear violation of specific constitutional rights or liberties. Frankfurter also expressed concern about setting a precedent where federal courts could intervene in state criminal proceedings based on subjective judgments about fairness or justice rather than concrete legal principles. He believed this would lead to an unpredictable and inconsistent application of the law.