What constitutes a warrantless arrest for a misdemeanor?

A warrantless arrest for a misdemeanor is properly justified when the offense is committed in the presence of a law enforcement officer. This principle is rooted in the legal concept that officers are allowed to act on their observations and directly intervene when they witness a crime being committed. This immediate presence allows them to take necessary action without needing a warrant, as they can ascertain the situation firsthand.

The other options do not provide sufficient grounds for a warrantless arrest in the context of misdemeanors. While evidence gathered at the scene or witness testimony might support a case, they do not grant the authority to arrest without a warrant unless the crime is observed live. Similarly, suspicion of potential crime may not be enough to justify an arrest, as it lacks the immediacy and direct observation required to make a warrantless arrest lawful.