A first responder is
[t]he initial responding law enforcement officer(s) and/or other public safety official(s) arriving at the scene.
The first responder uses a limited amount of equipment to perform initial assessment and intervention and is trained to assist other EMS providers. This level of provider is not intended to be utilized as the minimum staffing for an ambulance.
- Digital Evidence in the Courtroom: A Guide for Law Enforcement and Prosecutors, Glossary, App. E, at 73.