In the case of Ohio v. Roberts in 1979, the U.S. Supreme Court ruled on a matter concerning the Confrontation Clause of the Sixth Amendment, which guarantees defendants in criminal cases the right to confront their accusers. The defendant, Herschel Roberts was charged with forgery for passing off stolen checks and his accomplice's preliminary hearing testimony was used against him at trial because she could not be located to testify in person. The court had to decide whether this violated Robert’s rights under the Confrontation Clause or if it fell within an exception allowing hearsay evidence when a witness is unavailable but has given prior testimony under oath subject to cross-examination. The Supreme Court held that using such testimonies does not violate constitutional rights as long as they bear "adequate indicia of reliability". This can be established either by falling within a firmly rooted hearsay exception or bearing particularized guarantees of trustworthiness. This decision set forth what came to be known as “the Ohio v. Roberts test” for determining when out-of-court statements may be admitted into evidence despite objections based on confrontation clause grounds.

In the dissenting opinion for Ohio v. Roberts, Justice William Brennan Jr., joined by Justices Potter Stewart and Thurgood Marshall, argued that the majority's decision to allow hearsay evidence violated the defendant's Sixth Amendment right to confront witnesses against him. They contended that allowing such evidence based on its reliability was a departure from established precedent which required "unavailability" of a witness before their out-of-court statements could be admitted into trial. The dissenting justices believed this shift would lead to increased use of hearsay testimony in criminal trials, undermining defendants' rights and potentially leading to wrongful convictions due to unreliable or unchallenged testimonies. They also disagreed with the majority’s interpretation of “unavailability,” arguing it should only apply when a witness is physically unable or refuses to testify despite court orders.