Hypothetically, boating accident happens and somebody falls in the water cop comes up to me and ask if I can fly my drone up and down the river to see if anybody is bobbing in the water or on the shoreline. I am in D airspace. can I lawfully do that for that police officer? I am a Part 107 pilot so I should know this. my first impression is no because the FAA regulates the air not the police officer but it's an emergency how far can that go?