Some leave evidence stashes that can do the equivalent of talking. Those injure enemies after the victim is dead.
And there are “witnesses” to all massacres.
Drone strikes and accidents have a way of wiping out witnesses.
Have you ever read the book ELEANA. Written by a Greek refuge about what his mother sacrificed to save her children when the communist took over ( she gave her life).
. A real eye opener to how they manipulate and terrorize one small community at a time.