In the 1902 case of Connecticut Mutual Life Insurance Company v. Hillmon, the U.S Supreme Court was tasked with deciding on an issue related to evidence admissibility in a life insurance dispute. The controversy arose when John W. Hillmon's wife claimed her husband's life insurance after he allegedly died during a trip. However, three different insurance companies contested this claim, arguing that the body found wasn't Mr.Hillmon but another man named Walters who had planned to travel with him based on letters they obtained written by Walters himself stating his intentions to join Hillmon on his journey. Mrs.Hillmon argued these letters were hearsay and shouldn't be admitted as evidence since Walters couldn’t be cross-examined about their content because he was presumed dead too. The court ruled in favor of the insurers allowing them to use Walter’s letters as evidence under what became known as "the state-of-mind exception" to hearsay rule which allows statements describing one’s future intent that directly affect the outcome of events being litigated into evidence even if it is considered hearsay.

In the dissenting opinion for Connecticut Mutual Life Insurance Company v. Hillmon, Justice Harlan disagreed with the majority's decision to allow hearsay evidence in this case. He argued that it was a dangerous precedent to set and could lead to potential abuses of justice. He believed that allowing such evidence would undermine the reliability and integrity of court proceedings by permitting second-hand information which may not be accurate or reliable. Furthermore, he contended that there were other ways for the prosecution to prove their case without resorting to hearsay evidence, making its inclusion unnecessary and potentially harmful. In his view, upholding traditional rules regarding admissibility of evidence was crucial in maintaining fair trials and ensuring just outcomes.