Not only in North America. In Europe too. Remenber Liu Shaoyo in Paris 2017? He was killed in his home by the french Police.@Jura
Read up this database from the Washington Post to learn how the police in The Shining City on a Hill works:
An example from Toronto:
An 18 year old man (teenager according to the definition by the Western media on the shooting of the moron in HK) was holding a small knife on an empty streetcar. A cop got on the car and shot him six times. The court ruled the first three shot was justified but the last three (shot at his corpse on the floor) was overkill. The cop was convicted of guilty of attempted murder.
In North America, cops are free to kill if they feel their lives are threatened