The police have to treat even the most extreme atrocities as a matter of criminal procedure--once the immediate threat is past. (In the recent London Bridge attack, the suspect was shot dead on the scene, on the theory that he posed an ongoing immediate lethal threat. The victims were in the area attending a conference on educational programs in UK prisons called Learning Together. But again, outside of immediate self-defense:
Don't forget our other theme, brought to you by all our detectives plus economic analysis (overview by one of my colleagues is here): do your first choice field.
UPDATE: The Washington Post published the Afghanistan Papers on December 9th, called, as noiristas might predict, "At War with the Truth." Original research and archival material.