Even if it was so, one shot would do it, may be only wounding. Yet he had the right to kill, he used it like others. Shooting multiple times or chock holding to make sure that target is dead is execution . They could have shot Garner in leg, instead they used the right to kill.
The killings at will are part of the Dominant Force law enforcement framework. In short - instilling fear as anything can happen to you, your live and death are at their will. That fear is supposedly makes you behave "good". It is a violation of civil rights of general population the same way like sniper rifle prominently targeting demonstrators (another piece of the Dominant Force) is a violation of the demonstrators' 1st Amendment rights (by generating chilling effect)
The killings at will are part of the Dominant Force law enforcement framework. In short - instilling fear as anything can happen to you, your live and death are at their will. That fear is supposedly makes you behave "good". It is a violation of civil rights of general population the same way like sniper rifle prominently targeting demonstrators (another piece of the Dominant Force) is a violation of the demonstrators' 1st Amendment rights (by generating chilling effect)