Can a search and seizure be reasonable if it is not authorized by a warrant?

Yes, a search and seizure can be considered reasonable without a warrant under certain exceptions, such as exigent circumstances, consent, or when evidence is in plain view. The Fourth Amendment allows for these exceptions when immediate action is necessary to prevent the destruction of evidence, ensure officer safety, or protect the public. However, the justification for such actions must be clearly established and often scrutinized by courts to ensure they adhere to constitutional protections.