What defines a "citizen's arrest" under California law?

The definition of a "citizen's arrest" under California law specifically involves detaining someone for a crime that the individual making the arrest has witnessed taking place. This means that the person must have direct knowledge of the criminal act occurring in order to legitimately detain the suspect. This standard protects the rights of the individual being arrested, as it ensures that only those who have firsthand knowledge of an offense are allowed to act in this capacity.

The other options do not capture the essence of a citizen's arrest as defined by law. Arresting someone based on mere suspicion lacks the necessary evidence of witnessing the crime. Reporting a crime to law enforcement is not an arrest and does not empower a citizen to detain anyone. Arresting someone for a past crime also misinterprets the framework of citizen's arrest, which is contingent upon witnessing a crime in real-time, rather than addressing offenses that occurred previously without current observation.