The police ask to be police; I don't care about occupational hazards; I'm more concerned with people going to work and not coming back home because of a cops paranoia or attitude problem. And it's not interesting to me to determine which percentage of cops are guilty of misconduct; the problem is that the system as a whole is was not designed to protect justice or the citizens of the US but the people who run it and the people it was set up to protect (the wealthy) so you'd not expect it to do a very good job of protecting poor black people. Whether 1% or 60% of cops overstep the mark, murder, frame, torture etc? Not really a very interesting statistic.
The various news sources in the UK have no reason to attack the US police; i'm not sure where you get that from; perhaps it's something you say when someone receives information you don't agree with or find damaging to your beliefs. Statistics; simply the number of dead; don't really lend themselves to much to "narratives".
I don't think it's naive not to be a conspiracy theorist. Sure, there are some cases of police murders and other misconduct but it's hardly the norm and it is rather spurious to think every run-in with the police lurks the head of a grand conspiracy or a cover-up.
When you watch the news in the US from the UK, keep in mind that many have a vested interest in telling a certain narrative.