I've actually traveled internationally and worked in tough areas. US police / customs etc are not corrupt (relative to developing countries I've traveled in). This really makes me lose confidence in Amnesty unfortunately.
The US is relatively violent compared to developed peers and has some insane pockets of violence (east st louis etc). No question about that. This is stark when traveling to Asia or Western Europe - even "bad" areas in places like Germany are ridiculously safe relative to "bad" areas in the US. And that includes interactions with police (often unarmed overseas vs jumping on your back with a gun in the US).