Oh, those nagging little details. The medical examiners report states that Garner died of compression to his neck and that compression to his chest probably also contributed to his ultimate death. It is a homicide, like it or not. In short, the cops did, as a matter of medical fact, kill him. He did not have some unrelated heart issue at some time later that same day (as some seem to want others to think for whatever their own reasons are.) This info is public, not disputed, and super easy to find.
Also brush up on the fact that his own wife does NOT believe that race had anything to do with the entire thing. As she said, Garner and the cops knew each other well. Cops would call him "cigarette man" and who knows what Garner called them. He's too dead to answer for himself at the moment.
There are some who just want to beat the drum that all cop killings of civilians would cease immediately if black people, and apparently only black people, would just stop resisting arrest. Why is it that in a time when murder, robbery, rape are all down (by all races) that killings of civilians (of all races) by cops is up? Personally I would guess it's a culture of fear combined with militarization and training that requires that cops think of their work place as a war zone when it isn't. That data is also known to be under reported with nearly all agencies saying that nearly 100% of killings were justified even though they don't report them.
Some related reading for the interested few:
Hundreds of Police Killings Are Uncounted in Federal Statistics - WSJ