I would say the best example of how they kill is what took place at Waco. For a moment just assume the Davidians were all nuts (which they were not) the BATF intentionally killed the 'hostages' (children).
There was no remorse or proper investigation. These people are bloody killers. Don't you forget that.
They've never dared to attempt to subjugate an armed populace. Like us. Don't you forget that.