What term is used for the first officer who arrives at a crime scene?

The term for the first officer who arrives at a crime scene is "First responder." This designation is essential in the field of law enforcement because the first responder plays a critical role in securing the scene, providing immediate assistance to any victims, and ensuring that evidence is preserved. This officer is typically the first to assess the situation, gather preliminary information, and take necessary actions to manage the scene until further investigative resources arrive.

The role of a first responder is distinct from that of a crime scene investigator, who arrives later to conduct a detailed examination of the crime scene and collect forensic evidence. Detectives are specialized investigators who often handle follow-up inquiries and case management, and they usually show up after the initial responding officers have done their preliminary work. The term "officer in charge" may refer to any officer designated with authority over a scene, but it is not specific to the first officer on the scene. Hence, "First responder" accurately captures the role defined in the context of the question.