Wiktionary
on-scene
a. At the site of an incident
Usage examples of "on-scene".
He directed the operation, but the on-scene commander was his son, Commodore Roderick Brady-Schiavona—the one who fooled the Tarakans so beautifully year before last.
Peabody, cozy up with some of the uniforms, first on-scene was Lewis and her partner.