The US system is bad but a lot of police systems worldwide are bad, the US one is just bad in different ways. In terms of generic corruption, our police force is relative trustworthy AFAIK. The main issues are the militarization and the racism.
I don't think we really need to imitate other countries so much as we need to lose the whole "support the police" attitude. Every time one of these murders happens, people come out of the woodwork supporting the cops and expressing support for cops in general, as if to imply that a criticism against that one cop is a criticism against all cops. Its not just random citizens, its journalists, politicians, apparently legal professionals and whoever the fuck is on grand juries...
In most fields, its understood that there are standards and that people and organizations that don't meet those standards need to change or be forced out of the industry. Do doctors try to stop other doctors from having their medical license revoked? Do researches try to defend quacks who release shitty studies like the vaccines cause autism thing? Do lawyers try to stop other lawyers from being disbarred? As a whole, no. Just because that one person is punished for doing a bad job is none of their business, and I'm willing to bet that many professionals who take pride in their work hate the incompetents and conmen in their industry more than the average person.
But policing, one of tiny handful of jobs where you're allowed to fire lethal weapons at people, we can't have professional standards for that. Cops need to look out for each other, and if a cop does fuck up and kill someone then its the responsibility of the cops to decide how they should be punished. Its like a gang, they're protecting each other against everyone else. They don't think of themselves as just doing a job. Which on its own is a problem, but it becomes an almost insolvable one as long as everyone, especially people in power, supports them in acting this way.