The video shows McGrier loudly asking the officer why he is being stopped before he is pushed into a wall by the officer, then punched repeatedly before being tackled onto rowhouse steps. McGrier tries to deflect the punches but does not appear to throw any in return. Another officer stands by and tries to hold McGrier's arm.
McGrier's attorney, Warren Brown, said the officer had a run-in with his client in June when he was charged with assaulting the officer, disorderly conduct, obstructing, hindering and resisting arrest, the Sun reported.
Neither officer has been identified. One officer is suspended but it is unclear whether it is paid or unpaid. The status of the second officer is pending the investigation, the Sun reported.
"We are working day and night to bring about a new era of community-based, Constitutional policing and will not be deterred by this or any other instance that threatens our efforts to re-establish the trust of all citizens in the Baltimore Police Department," Mayor Catherine Pugh, who called the video disturbing, told the Sun.
The department has faced increased oversight since entering a federal consent decree in 2017 after the U.S. Justice Department determined officers routinely violated people's Constitutional rights, the Sun reported. The investigation was sparked by the 2015 death of Freddie Gray, 25, who suffered injuries while in police custody.