The probe comes after a series of videos showed officers brutally beating Black motorists.

The Justice Department opened a civil rights investigation Thursday of the Louisiana State Police, launching the review after a series of videos showed officers brutally beating Black motorists.

One particularly violent video showed state troopers punching, stunning, and dragging an unarmed man, Ronald Greene, as he apologized for failing to stop during a high-speed chase in 2019. He died shortly after, but state police initially told his family that he was killed when his car hit a tree. They refused repeated requests to release the police video.

“We find significant justification to investigate whether Louisiana State Police engages in excessive force and in racially discriminatory policing against Black residents and other people of color,” said Kristen Clarke, the assistant attorney general in charge of the civil rights division.

The investigation will review state police policies, training and supervision as well as how the use of force is investigated internally. It will also examine how the agency reviews complaints and disciplines officers.

Members of Congress and civil rights groups, including the American Civil Liberties Union, urged the Justice Department to investigate, accusing Louisiana State Police officers of targeting Black people, using unreasonable force against them, and then trying to conceal their actions.

State Police Superintendent Lamar Davis has said he would welcome the Justice Department investigation. Two-thirds of his agency’s uses of force have been directed at Black people, he told the Associated Press, which published some of the most troubling videos.

The AP investigation found that Greene’s arrest was one of least a dozen over the past 10 years in which state police troopers or their superiors ignored or concealed evidence of beatings.

The state Legislature has planned to hold a hearing to examine what Gov. John Bel Edwards knew about the incident and the police video. His senior legal aide, Matthew Block, wrote to the committee chairman that his office is “confident that this testimony will demonstrate that neither the governor nor anyone on his staff had any role in any attempt to cover up the facts related to Mr. Greene’s death.”

Under Attorney General Merrick Garland, the Justice Department has opened similar investigations of police departments in Minneapolis after the death of George Floyd and in Louisville, Kentucky, following the death of Breonna Taylor. It is also investigating police departments in Phoenix and Mt. Vernon, New York.

These investigations often lead to agreements in which the police departments agree to abide by court-approved changes in how they operate to reduce violations of the civil rights of people they encounter.