What would be a modern-day similar incident to the Boston massacre?

The most similar would probably be Bloody Sunday an incident on 30 January 1972 where British soldiers of the Parachute Regiment fired into demonstrators killing 13 men.
A similar shooting is the Greensboro massacre of November 3, 1979, when 5 protest marchers were shot and killed by members of the Ku Klux Klan and the American Nazi Party.