Can they? I've heard of police in Japan pinning murder cases on people they don't like. I believe there has been some reporting on this related to why thy have such high clearance rates. Don't the police in the UK still have a lot of sexual misconduct scandals?

In England the police arrests you for a tweet under hate speech laws and they threw the post office workers under the bus to protect the politicians and buggy SW of Fujitsu. Not the place where I'd trust the law enforcement at all.

And Japan, while being clean, safe and Kawai, its legal system has like a 90%+ conviction rate, so make of this what you will.