tl;dr – After ruling out military and commercial sources, they still have no idea who was running the drones.

Sightings include a few interesting details… There appears to have been clusters of 10-30 smaller drones being controlled by a larger stationary drone which was around 6 feet across. All of the drones stayed in the air for 2-3 hours (which seems like an unusually long period?). Observations through night vision goggles described the large drone as having four arms with propellers, and some drones may have been fixed-wing with a 10’ wingspan. The most curious thing is that no sound was ever reported even from the large drone. The sightings stopped almost immediately after a large investigation was announced, but as far as anyone was concerned, no laws were ever broken.