Inquiry into Mexico's [deadly repression from 1965 to 1990]obstructed by militaryand other agencies, board says.

This repression included theTlotelolco massacre in whichsoldiers secretly posted by the president in a nearby large building shot a crowd of protestingstudents down below.

There were, of course, cops outside that were sent officially to control the protest — but thosecops were not the ones that opened fire. ISTR hearing that the hidden soldiers shot at them so thatthey would shoot "back" at the only possible visible enemy.