Darling, the police of a Socialist state are not equivalent to the police of capitalists. They have completely different motivations. Police under capitalism exist to protect private property and nothing else. The function of the police in a worker’s state is the same as in that of a bourgeois state: enforcing the class interest of the ruling class. The difference lies in who constitutes the ruling class.

Yeah western media are generally known to not ever spread atrocity propaganda, particularly against China.

were almost certainly subject to abuse by police while in custody

Doubtful. There were no credible reports.