I’ve said this before both here:
https://blog.hsoi.com/2009/02/14/a-simple-experiment/
and here:
https://blog.hsoi.com/2014/08/19/unarmed-≠-undangerous/

While the specifics of particular incidents need to be evaluated upon the specifics if that incident, there is a general (mis)perception by the public that an unarmed person is somehow not dangerous, that there isn’t potential for danger or death. The perpetuation of this blanket fallacy needs to be stopped.