Comments from feedback form - "Facial wounds,no customers or ..."
Facial wounds,no customers or staff were hurt and then people were shot? The four people that had facial wounds was a result of the shooting. They might have not been shot in the face? Did they get them from the party before hand. Poorly written.
Learn to read. "Four, including the gunman who had facial wounds, are being treated ..."
This is a common use for the comma; to separate a clause without which the sentence could stand alone. You have read as-if the comma was placed after the word gunman.