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 South Carolina, 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 obtain a search warrant before conducting a search that would otherwise violate an individual's reasonable expectation of privacy. However, there are several 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 or someone's safety is at risk (exigent circumstances). Additionally, the evidence 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, and it must be reliable, meaning it is trustworthy and its integrity has not been compromised. If evidence is obtained in violation of these principles, it may be excluded from trial under the exclusionary rule, which is designed to deter police misconduct and protect citizens' Fourth Amendment rights against unreasonable searches and seizures.