Tear-gassed, beaten and dragged. Protesters in Hong Kong have accused the police of using excessive force during a political demonstration in June. Hong Kong officials have pushed back. “My officers are acting in accordance with our guidelines.” The New York Times analyzed hundreds of videos, spoke to protesters who were beaten and interviewed experts in crowd control. We identified seven incidents caught on camera that contradict official statements and show that police officers did use excessive force, according to experts. On June 9, one million people took to the streets to protest a bill that would allow Hong Kong to detain and extradite people to mainland China. The proposal stoked fears over the erosion of civil liberties that have long set Hong Kong apart from the Chinese mainland. Protesters’ demands went unheeded. And days later, on June 12, lawmakers put the bill to a vote. Thousands gathered at the government headquarters in protest. The demonstration was mostly peaceful, but a small group of protesters threw objects at officers in an attempt to breach police lines. Officers responded, beating protesters with batons and using tear gas and riot control ammunition indiscriminately. Peaceful demonstrators found themselves in the middle of the chaos. Ying-mo, a retired mechanic’s instructor, was watching the protest. In this video, we see him unarmed walking toward police. An officer aims a gun, likely loaded with balls containing pepper spray. A popping sound is heard. Ying-mo falls to the ground. Three officers pick him up and carry him away. Ying-mo was charged with participating in an unlawful assembly and released on bail. What happened to him was not an isolated incident. In this video, another protester stands near officers. Riot police pull him to the ground and beat him. He is taken to the sidewalk and arrested. In another incident, a man who is distributing water is attacked by the police. Officers pepper spray him, punch him and beat him with batons. One officer puts him in a chokehold. In some cases, commanders participate in the violence. They are identified by white shirts. When this protester falls to the ground, two commanders are among a group of police who attack her with batons and shields. And this woman said she was dragged for about 150 meters to the legislative council by a commander. All of the protesters shown here were arrested and later released, some on bail. Dr. Rohini Haar, an expert in crowd control, said these police actions were unjustified. Some of the most chaotic scenes happened when police fired tear gas at protesters trapped outside an office building. Early on that day protesters set up barricades on the street. Around 3 p.m., officers surrounded the building on both sides, firing tear gas. Trapped by the police and barricades, protesters rushed toward the tower’s main entrance. Those who make it inside attempt to open locked doors to allow more people through. But the police continue to fire tear gas into the crowd. Ivy Chan was volunteering at the protest, assisting people outside the tower. Dr. Haar said the police caused unnecessary panic. As violence escalated, Wu Chi-wai, a prominent Hong Kong lawmaker, walked the front lines. As he moves toward the police, a commander directs another officer to fire tear gas. He continues marching, and a second canister is fired. Anna Feigenbaum, an expert in the use of tear gas, said that it should never be used like a firearm. We sent these videos to the Hong Kong police, but they did not respond to our request for comment. At least 81 people were injured in the demonstration, according to the Hong Kong government. Police have said 22 officers were injured. Officials have promised an investigation into police actions, and the extradition bill was suspended after June 12. But protesters want more. They are asking for an independent inquiry and the full withdrawal of the bill.