"The FAA wants to enlist the assistance of local law enforcement. To assist the FAA in gathering information about suspected unauthorized UAS activities, law enforcement can provide invaluable assistance by: Identifying and interviewing potential witnesses. Identifying the UAS operator. Viewing and recording the location of the event for follow-up FAA investigation. Identifying sensitive locations, events or activities subject to temporary flight restrictions or other prohibitions on flight operations. November 28, 2017 - 2 of 5 - by Michele Coppola Notifying one of the FAA Regional Operation Centers of the incident as soon as possible when the event poses an imminent danger to other aircraft or has resulted in accident/injury. Collecting and preserving evidence the FAA can use in its investigation."
This is a cut & paste of a part of Astro's attachment. The very last sentence; "collecting and preserving evidence the FAA can use in it's investigation" is where my contention of local law enforcement acting as an agent for the FAA comes from.