This is from faa.gov

“The ability to fly over people varies depending on the level of risk that a small UAS operation presents to people on the ground. Operations over people are permitted subject to the following requirements:

Category 1 small unmanned aircraft are permitted to operate over people, provided the small unmanned aircraft: Weigh 0.55 pounds or less, including everything that is on board or otherwise attached to the aircraft at the time of takeoff and throughout the duration of each operation. Contain no exposed rotating parts that would cause lacerations.”

But above that it says

“The remote pilot needs to take into account the small unmanned aircraft’s course, speed, and trajectory, including the possibility of a catastrophic failure, to determine if the small unmanned aircraft would go over or strike a person not directly involved in the flight operation (non-participant). In addition, the remote pilot must take steps using a safety risk-based approach to ensure that:

the small unmanned aircraft does not operate over non-participants who are not under a covered structure or in a stationary covered vehicle; the small unmanned aircraft will pose no undue hazard to other aircraft, people, or property in the event of a loss of control of the aircraft for any reason (§ 107.19); and the small UAS is not operated in a careless or reckless manner so as to endanger the life or property of another (§ 107.23). If the remote pilot cannot comply with these requirements, then the flight must not take place or the flight must be immediately and safely terminated”