On Saturday night DeRay McKesson, a well known Black Lives Matter activist, was arrested in Baton Rouge, Louisiana, during a peaceful protest over the deaths of Alton Sterling, Philando Castile, and other minorities at the hands of police.

The out activist—who was one of 100 demonstrators taken into custody—livestreamed his arrest on Periscope.

Vice reports:

He was filming as protesters marched up Airline Highway at about 11.15 pm. The video shows lines of flickering police lights in the distance. McKesson realizes that police are arresting protesters and stops to record video of the interactions.

Then one officer points at McKesson and approaches him.

“Watch the police, they are just literally provoking people," McKesson said during his Periscope video.

Officers warned McKesson about walking over the line in the road, and then arrested him—though it did not appear he crossed the line.

After McKesson was taken into custody, his phone was passed onto other protestors, who kept filming.

"In a booking record, the Baton Rouge authorities said Mr. McKesson ignored a police officer’s order to stay out of the road. He was charged with simple obstruction of a highway of commerce," reported the New York Times.

McKesson was active on social media during the protest. Watch some of the videos he posted throughout the night below:

Maya Liu, a criminal justice reporter for The Baton Rouge Advocate was on the scene, and interviewed a Louisiana State Police Officer about the accusations that the police were aggressive, not the protestors:

“Well, they’re clearly blocking the roadway," the police officer told Liu. “We welcome the protests. We want them to voice their opinions. That’s what we’re here to do, to make sure they’re safe and they’re able to do that."

As news spread of McKesson's arrest, the #FreeDeRay hashtag began trending on Twitter, with many people urging the Baton Rouge Police Department to free McKesson. As of now there is no word on when he will be released from custody.

McKesson had traveled to Louisiana Saturday morning to join the protestors.