Protesters have accused the Hong Kong police of using excessive force throughout the demonstrations that have gripped the city for the past four months. But on the night of Aug. 11, a major shift occurred. For the first time, officers disguised as demonstrators were seen beating protesters and conducting arrests.
Videos of the night went viral. They showed undercover officers hitting protesters with batons and pinning them to the ground, leaving some bleeding profusely. We analyzed footage of the night and spoke to more than a dozen witnesses and protesters who were detained. Lawyers and human rights advocates who watched the images say the police used excessive force to conduct arbitrary arrests.