For evidence to be admissible in a criminal prosecution it generally must have been obtained legally—with a search warrant, or based on an exception to the search warrant requirement, such as consent to search—and be relevant and reliable.
In Hawaii, as in other states, evidence must be obtained legally to be admissible in a criminal prosecution. This means that law enforcement officers typically need to have a valid search warrant before conducting a search that results in the collection of evidence. However, there are exceptions to this requirement, such as when an individual gives consent to a search, when evidence is in plain view, during exigent circumstances, or when the search is incident to a lawful arrest. Additionally, for evidence to be admissible, it must be relevant to the case, meaning it must have a tendency to make a fact of consequence more or less probable than it would be without the evidence. The evidence must also be reliable, which generally means that it must be trustworthy and its integrity has not been compromised. Hawaii follows the Hawaii Rules of Evidence, which are similar to the Federal Rules of Evidence, in determining the admissibility of evidence in criminal proceedings.