He should have used a tazer. There is absolutely no reason to use deadly force.
Their department didn't have Tazers. The use of force is circumstantial and based on a matrix.
For example: If Subject A is 6'5 350lbs, and Officer B is 5'8 and 190lbs, the use of any type of force is, by physical observation, more acceptable compared to if the Officer would have been 6'3 280lbs. If that makes sense.
On another note, the officer who put Garner in a chokehold SHOULD have been indicted as well as fired (don't know if he was or not, not following the story).
There was no perceived threat with Garner. Chokeholds were banned by the NYPD in the 80's, yet this officer, surrounded by MULTIPLE officers, performed it.
Even in these two cases, there is a huge disparity between the context of what occurred.
In my humble opinion, if Darren Wilson was a racist and a bad cop, he could have easily said that he was jumped by Brown and his friend, and he was forced to shoot. He didn't. He described the event according to much of the evidence (Brown's blood in the cop car, etc.). He provided a statement and it did not change based on the evidence.
Mike Brown's death was tragic but it was not a case of brutality and racism.
Garner's case... racism? Maybe. Brutality/Excessive force: Definitely. The cop who put Garner in a chokehold had no reason to fear for his life based on the evidenced series of events (video), as opposed to Officer Wilson, who's testimony matches the series of events that unfolded.
The problem is that there was no evidence, so Brown's family, friends, the media and the country was forced to speculate what happened, and in their minds it made sense.
There was a shooting of a black man in Ferguson days following Mike Brown's death. no protests, no marches, no media coverage. Why? Because someone was filming. Dude had a knife and charged the cops.
Garner is different. There was physical evidence, but that is piss-poor training and coordination on NYPD's part, which they should be ashamed about.