This article compares the numbers, but doesn't go into the causes or the history of police brutality...
Was police brutality a major problem in the European societies in the past? If so, how did the European countries deal with that, and why the US didn't manage to? If not, why did that problem arise in the US specifically? Is police brutality a relatively new problem in the US, or does it have long history?
Thanks!
In a related thread here, u/lawdoggingit gave a great answer on the history of US law as it relates to policing, and I gave an answer setting out the specific circumstances around the foundation of the British police forces and how and why 'policing by consent' was made a major pillar of their operation.
If I may briefly summarise his lengthy answer, he suggests that the Nixon era brought several factors together (notably rising civil unrest over Vietnam, hardening offical attitudes to crime and the role of the police, the War on Drugs and the Kent State shooting), which put in place a criminal justice system where all components are incentivised primarily to punish, and that it has persisted to this day.
As I noted in my other reply, it's a complex issue but my answer can be found here