On October 22, just before dawn, hundreds of people, including many families, gathered and prepared to march toward the Dakota Access pipeline construction site near Standing Rock, North Dakota. Native American organizers lit sage and prayed for protection from police brutality before setting off on the 8-mile trek. Many in the crowd were emotional as they stood over what was once their ancestral burial grounds. Just last month, construction workers and contractors destroyed the site in preparation for installing the pipeline.

Aside from the desecration of sacred sites, critics argue, the environmental hazards caused by the pipelines and the possibility of a spill will be catastrophic. Members of the Standing Rock Sioux tribe and reservation, which is located just a mile from the construction sites, say the pipelines will contaminate their drinking water and pollute the Missouri River.

The march was undertaken in solidarity with several protesters who had chained themselves to bulldozers and pipeline machinery at the construction site. But the marchers never made it to their destination. Instead, they were attacked by police forces who used pepper spray and beat protesters with batons. Dozens of officers, backed by military trucks, police vans, machine guns, and nonlethal weapons, violently approached the group without warning.

“Don’t move, everyone is under arrest,” said a voice from the loudspeaker of the military vehicle.

As the protesters attempted to leave, the police began beating and detaining them. Several Native American women leading the march were targeted, dragged out of the crowd, and arrested. One man was body-slammed to the ground, while another woman broke her ankle running from the police. The military and police trucks followed the protesters as nearly a hundred officers corralled the protesters into a circle. Among the arrested were journalists, a 17-year-old pregnant girl, and a 78-year-old woman.

In total, more than 140 people were detained in half an hour. It was the largest roundup of protesters since the movement against the pipelines intensified two months ago. A majority of those arrested were charged with rioting and criminal trespass. Overall, close to 300 people have been arrested since protests against the pipeline kicked off over the summer.

When we arrived in Mandan, the jail was so overwhelmed with people that we had to sit on the floor in the jail’s common area. Two Native American men were thrown into solitary confinement. A number of women faced humiliating strip searches, which included spreading their body parts and jumping up and down while coughing. We were refused phone calls and received no food or water for eight hours after being arrested. Two women fainted from low blood sugar and another had her medication taken away, causing her to shake and sweat profusely.

When I was released from jail, my camera was missing. When I asked about its whereabouts, a police officer said, “Your camera is being held as evidence in a crime.”

The video footage presented here was shot from the beginning of the march, during the prayer, and ends the moment I was arrested. Many families, nearly all of them Native American, can be seen running for the hills. Many people told me they felt as though they were re-enacting the massacres of the Lakota nation during the westward expansion of the United States, when families were shot in the back as they fled.