@cdarwin IANAL, but from what I've seen of US case law, when police fail to self-identify as such and, while not recognizably police, impose imminent risk death or grievous bodily harm (which is generally presumed in cases of kidnapping), if the attacked person survives police-gang revenge, the trial outcome usually depends on the race of the person asserting self-defence to excuse use of lethal force against an assailant.
https://www.motherjones.com/politics/2014/10/texas-no-knock-swat-raid/
However, there was one at least one exception case: that of Cory Maye.
https://en.wikipedia.org/wiki/Cory_Maye