amphotora/iStockBy IVAN PEREIRA, ABC News(BOSTON) — A Boston police sergeant has been placed on administrative leave, and an investigation is underway after body camera footage was released Friday that showed officers violently clashing with protesters during a Black Lives Matter demonstration in May.In one of the videos, an officer is seen boasting about hitting a protester with their vehicle.The video was posted by the news site The Appeal and showed officers using mace on protesters, making comments about attacking the demonstrators and charging at them during the May 31 event, shortly after George Floyd was killed in Minneapolis.In one of the videos, an unidentified officer is seen talking with another about striking a protester with their vehicle. When the officer finds out they’re being recorded on a body camera, they begin to change their story.Attorney Carl Williams, who is representing some of the protesters who were arrested that night, obtained the footage as part of discovery in his case against the city and the officers and provided it to The Appeal.Boston Police Commissioner William Gross released a statement Friday in response to the videos and said he ordered the Bureau of Professional Standards to conduct an investigation.“I have placed a sergeant involved in this incident on administrative leave, and I will take any additional action as necessary at the conclusion of the investigation. I want to encourage people to bring these matters to our attention so that we can investigate them appropriately,” Gross said in a statement.The Boston Police Patrolmen’s Association, the union representing Boston police officers, released a statement Saturday and said the footage didn’t tell the full story, as they say “hundreds” of officers were “treated for trauma and injuries” they received from protesters.“The reality-altering effort and insult aside, the fact remains, the violence and hatred perpetrated against our officers and our city that night will forever be engrained in the minds of our officers,” the union said in a statement.The BPPA accused Williams of editing the footage, and Williams responded, contending that he gave the unedited body camera footage. The Appeal said Williams was given 44 videos and more than 66 hours of footage as part of a discovery file in his case.“I didn’t stitch any snippets together,” Williams tweeted. “And why do you all hate anarchists so much? Do you just think having a prejudice against specific political beliefs is acceptable?”Copyright © 2020, ABC Audio. All rights reserved.