No-Knock raids are a controversial tactic where law enforcement officials break into a residence without announcing themselves to the occupants or identifying themselves as police officers. The downside to this tactic should be obvious: that the targets of these raids may mistake the police officers for burglars, especially when such raids are done in the dark. This has resulted in multiple cases of police officers and even children being killed.
One specific case is the raid on Marvin Louis Guy, whose home was targeted under the false suspicion that the house contained drugs. Assuming that the police were home invaders, he retrieved a gun and opened fire, killing one officer and injuring three. Guy was unjustly charged with murder, despite only defending himself.