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Under common law, a statement made by a person who has been mortally wounded may be admissible in Evidence during trial for his murder or manslaughter, even if it is Hearsay. That is, if X told Y that he, X, was stabbed by Z, then Y might be able to adduce evidence of X's statement in court. Evidence of an out-of-court statement such as this would normally not be admissible at all (Admissibility Of Evidence). The rationale for admitting a dying declaration is that it is assumed that a person who is dying, and knows this to be the case, is unlikely to lie.

To be admissible, the declaration must be made by a person who has a 'settled, hopeless expectation of death' (R v woodcock (1789)). The declaration will not be admissible if it can be shown that the victim harboured even a slight hope of recovery (R v jenkins (1869)), but the victim need not be within moments of expiring when he makes the statement (R v bernadotti (1869)).

When the Criminal Justice Act (2003) comes fully into force (it is not in force at the time of writing), the law on dying declarations will become obsolete. s.116(2)(a) provides that any statement -- including an oral statement -- made by a person who dies before the trial prima facie admissible.