S7 E16 Evidence Law: Hearsay and exceptions: Declaration against interest + Res gestae + Present sense impression + Learned treatise + Implied assertion + Ancient document

Declarations against interest are an exception to the rule on hearsay in which a person's statement may be used, where generally the content of the statement is so prejudicial to the person making it that they would not have made the statement unless he believed the statement was true. The Federal Rules of evidence limit the bases of prejudices to the declarant to tort and criminal liability. Some states, such as California, extend the prejudice to "hatred, ridicule, or social disgrace in the community."

The admissibility of evidence under the declaration against interest exception to the hearsay rule is often limited by the Confrontation Clause of the Sixth Amendment.

A declaration against interest differs from a party admission because here the declarant does not have to be a party to the case, but must have a basis for knowing that the statement is true. Furthermore, evidence of the statement will only be admissible if the declarant is unavailable to testify.

Res gestae (Latin "things done") is a term found in substantive and procedural American jurisprudence and English law. In American substantive law, it refers to the start-to-end period of a felony. In American procedural law, it refers to a former exception to the hearsay rule for statements made spontaneously or as part of an act. The English and Canadian version of res gestae is similar but is still recognized as a traditional exception to the hearsay rule.

In the law of evidence, an implied assertion is a statement or conduct that implies a side issue surrounding certain admissible facts which have not necessarily been complied with the rules of relevance. There is varying opinion of whether hearsay evidence of implied assertions should be admissible in court to prove the issue within contents. While they are considered hearsay, they are generally considered to some extent unreliable than regular statements which are less easy to be fabricated.

A present sense impression, in the law of evidence, is a statement made by a person (the declarant) that conveys his or her sense of the state of an event or the condition of something. The statement must be spontaneously made while the person was perceiving (for example, contemporaneous with) the event or condition, or "immediately thereafter." The permissible time lapse between event and statement may range from seconds to minutes, but probably not hours. The subject matter and content of the statement are limited to descriptions or explanations of the event or condition, therefore opinions, inferences, or conclusions about the event or condition are not present sense impressions. An example of present sense impression is of a person saying, "it's cold" or "we're going really fast".

A learned treatise, in the law of evidence, is a text that is sufficiently authoritative in its field to be admissible as evidence in a court in support of the contentions made therein.

With respect to authentication, an "ancient document" is one that may be deemed authentic without a witness to attest to the circumstances of its creation because its age suggests that it is unlikely to have been falsified in anticipation of the litigation in which it is introduced.