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 Rhode Island, as in other states, evidence must be obtained legally to be admissible in a criminal prosecution. This means that law enforcement officers are typically required to have a valid search warrant before conducting a search and seizing 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 a search incident to a lawful arrest, or in emergency situations where there is a risk of evidence being destroyed (exigent circumstances). Additionally, for evidence to be admissible, it must be relevant to the case, meaning it must have a tendency to make a fact more or less probable than it would be without the evidence. It must also be reliable, which means it must be trustworthy and credible. Evidence obtained in violation of these principles may be excluded from trial under the exclusionary rule, which is designed to deter police misconduct and protect individuals' constitutional rights.