In the 1903 case Crowley v. United States, the U.S Supreme Court ruled on an issue involving a defendant's right to testify in their own defense. The appellant, Mr. Crowley, was convicted of murder and sentenced to death by hanging after he confessed his guilt during police interrogation but did not testify at trial due to fear of self-incrimination under California law at that time which prohibited defendants from testifying in their own trials. On appeal, it was argued that this prohibition violated his constitutional rights as it denied him a fair opportunity for defense. The Supreme Court disagreed with this argument and upheld the conviction stating that while federal law permitted defendants to testify on their behalf if they chose so voluntarily; state laws prohibiting such testimony were not unconstitutional since states had discretion over procedural aspects of criminal trials within their jurisdiction unless these procedures infringed upon fundamental principles of justice or liberty. Therefore, even though Mr.Crowley was unable to present his version of events directly before jury due to existing state law; there wasn't any violation of constitutional rights because he still had other means available for presenting evidence and arguments in support of his innocence through counsel representation.

The dissenting opinion in the case of Crowley v. United States argued that the defendant's constitutional rights were violated due to an improper jury instruction. The justice believed that the trial judge erred by instructing jurors they could consider evidence from a separate, unrelated crime when determining Crowley's guilt or innocence for the charges at hand. This, according to the dissenting view, was prejudicial and compromised his right to a fair trial as it allowed extraneous factors into deliberations on this specific case. Furthermore, it was contended that such instructions undermined principles of justice and fairness which are foundational elements within American jurisprudence.