What’s the difference between a “mass public shooting” and a plain “mass shooting?”
Enormous differences.
Mass public shooting used to mean a rampage shooting of unrelated people in a public setting, where four or more people, not the shooter, were killed.
This was to differentiate rampage shootings, which the public was concerned about, and which was given enormous publicity, from ordinary gang shooting drive bys and domestic shootings/killings.
Those who wish us disarmed, changed the definition to expand to "mass shootings", which they defined as any shooting in which four people were injured, whether they were injured by gun fire, fleeing the scene, or being hit by a car, as I recall. This inflated the number of "mass public shootings" in the public mind. The difference in the numbers is about a hundred to one, as I recall.
Lott, in this research, uses the first definition which was used by the FBI for years.
The difference is one of propaganda.