Alphonso Wetmore was charged with the crime of counterfeiting and brought to trial in a United States Circuit Court. The jury found him guilty, but he appealed his conviction on the grounds that it violated his rights under the Fifth Amendment. Specifically, he argued that since no one had witnessed him actually committing any act of counterfeiting, there was insufficient evidence for a conviction. The Supreme Court ultimately rejected this argument and upheld Wetmore's conviction because they determined that circumstantial evidence could be used to prove guilt beyond reasonable doubt in criminal cases. Furthermore, they held that even if all witnesses were absent from an alleged crime scene or unable to testify about what happened there, other forms of proof such as documents or physical objects could still be considered sufficient evidence for a valid conviction.

In this case, the Supreme Court was asked to decide whether a defendant who had been convicted of murder in the District of Columbia could be pardoned by the President. The majority opinion held that such a pardon would not be valid because it violated Article II, Section 2 of the Constitution which gives Congress exclusive power over criminal cases within its jurisdiction. Justice McLean dissented from this decision and argued that while Congress does have exclusive authority over criminal matters within its jurisdiction, there is nothing in Article II or any other part of the Constitution which prevents a president from granting clemency for an offense committed against federal law. He further argued that if such pardons were prohibited then it would undermine executive powers granted by Article II and limit presidential discretion when considering requests for mercy. Furthermore, he noted that since presidents have historically exercised their right to grant pardons without interference from Congress or judicial review then they should continue to do so unless explicitly forbidden by constitutional language.