The worst direct mass murder in the USA in recent years was of the Branch Davidian families on 19 April, 1993, near Waco, 76 people (26 children among them) were murdered by Washington’s Delta Force, among others. News reporters who say the Las Vegas massacre was the worst get a demerit. Furthermore, the Branch Davidians were murdered near Waco, Texas, so the reporter who says the massacre at the First Baptist Church building was the worst in recent Texas history also gets a demerit.
Washington for its part, merits a millstone at the bottom of the Potomac River. Please note that i did not factor in the inside operation of the Twin Towers and Building 7 because i consider them to have been an indirect massacre.