I do to some degree but I don't support the US approach entirely and I would of preferred that he was brought in alive to face trial and due process BUT I agree with what the officer did to the extent of, this guy is on drugs and he is not calming down and I have seen the skinniest people drop the biggest guys and anyone is capable of anything at any given time
But that's exactly why you need a police system that works properly. If police work in pairs, wear stab-proof / bulletproof vests, are equipped with non-lethal weapons, have access to support, having training in psychology and unarmed combat and are taught how to deal with violent suspects then you can eliminate the need to use guns when dealing with unarmed suspects, as is the case in the UK. Further, when dealing with people off their head on drugs you need special training - pointing a gun at them and trying to use reason isn't going to work. People in the US are dying needlessly because the police system there is simply not resourced or trained to deal with situations properly, as well as a culture that supports an excessive use of force. I'm not defending the actions of the suspect here - he was clearly behaving in an unacceptable manner and his actions cost him his life. But he shouldn't have been killed and that is a clear and obvious failing of the justice system.
There was a video of another case where a man with a knife was running down the street in New York. In that police all ran after him, pointed guns and were shouting at him, while he seemed to be under the influence of drugs. The police lacked any coordination, any obvious command structure and they clearly hadn't been trained in basic psychology - it was pandemonium and unsurprisingly the guy ended up being shot about ten times and dying instantly. It's the same with police chases where you see a dozen police cars all speeding after a suspect - there's no strategy. I would say it's a joke but that's not appropriate when people are dying as a result of police incompetence (and by that I don't just mean the officers involved but the entire command structure).