In the USA police are granted the right to kill anyone if they feel threatened, that is they "fear for their lives" or believe that a suspect is an imminent danger to themselves or anyone else. Is this morally correct?
Every American has the right of self-defense, whether a civilian, a police officer or a member of the military.
If you are reasonably certain that if you don't respond to a threat, you are very likely to be killed (or merely seriously injured), you have the right to defend yourself. If the only means of defense you have is to kill your assailant, then by all means this is what you need to do.
Of course (unless there are half a dozen eyewitnesses who agree that you were about to be killed), you're likely to be arrested, and even prosecuted, and at the trial you'll hope to convince the jury that it was, indeed, self-defense.
But when the person at risk is a police officer, the situation is considerably different. For starters, these days, most American cops are equipped with body cameras, so the judge and jury can
see what happened, instead of
listening to testimony.
I would say from a practical standpoint it is wrong, for these days every person a police officer kills (particularly if they are black) can lead to riots and even further deaths, it would have been more economical for the police to take that risk and take a bullet for the stability of society, which we would assume is their job, to uphold the public trust first and foremost.
I'm no fan of the cops, so I understand your point of view. Nonetheless, police officers are not soldiers. They do not go into battle knowing that there's a reasonable probability that they'll be killed.
I don't know how much money you earn where you live, but where I live, no cop is paid enough to graciously sacrifice his life in order to avoid killing someone who intends to kill him.
As I already said, I'm no fan of the cops, as anyone who's read my posts over the past 25 years would know, yet even I don't expect them to take that kind of chance.
I'm much more disgusted when the cops kill someone who, indeed, has committed a crime or was trying to commit one, but obviously did not have the intention and/or the ability to harm anybody, much less a cop. Perhaps the sad story of Freddy Grey was covered in your local newspaper. Here in the Baltimore region it was in the headlines for months. His mother was awarded a six-figure settlement from the city, but that didn't bring her little boy home.