Under what circumstance can a police officer make a warrantless arrest for a misdemeanor?

A police officer can make a warrantless arrest for a misdemeanor if the misdemeanor was committed in their presence. This principle is grounded in the common law rule regarding the authority of law enforcement officers. The rationale is that when an officer directly witnesses a misdemeanor being committed, they are able to establish the elements of the offense and the identity of the perpetrator without needing to gather further evidence. This immediate observation provides the officer with the necessary factual basis to act promptly in order to enforce the law and prevent further violation.

In contrast, while probable cause is a standard for making arrests, it is typically applied to felonies or in situations where the officer did not witness the crime. Mere flight from the scene by the suspect is not sufficient on its own to warrant an arrest; the underlying crime must also be established. Lastly, the location (public place) alone is not a decisive factor; what matters in this context is that the officer actually observes the misdemeanor being committed. Hence, the presence of the crime is vital in allowing for the warrantless arrest.