How do you know this is a factor at all? Islamic terrorism was a notable problem and zero people planning or committing acts of terror had any illusions that they'd be held totally accountable and then some. Plenty of white domestic terrorists have been held accountable too--it's the norm, not the exception, once they actually do something.

I'm pretty sure you're not advocating taking action against groups that are suspected of possible future wrongdoing. (If you are: you're totally onboard with Trump's Islamic countries travel ban.)

(Also, your anecdote-vs-general-statement-with-no-evidence point about policing is not very compelling. Gendron is an especially bad choice as an example since police also apprehended Frank James without a struggle. If you want to be compelling, you have to use statistics here. Statistics do reveal a problem. But single examples won't cut it, because the phenomenon is not all-or-nothing; there is a lot of police violence against white people, including unarmed white people, too.)