The FBI has launched an official investigation after three white Missouri police officers were filmed allowing their K-9 dog to attack a Black man, St. Louis Post-Dispatch reports. In an email to the outlet, Woodson Terrace Police Chief Randy Halstead said his department is “fully cooperating” with federal agents in the probe.

The news arrives after the St. Louis County prosecutor’s office announced it would also investigate the Monday (Sept. 20) arrest. St. Louis Post-Dispatch writes that federal investigators have already requested information about the arrest from the police department.

As reported by REVOLT, police in Woodson Terrace, a city near St. Louis; were called to the area last week about a man who allegedly broke into a local business. Authorities claimed the man appeared to be on drugs, threatened officers and said he called himself a “sovereign citizen,” which is someone who believes they are not subject to government laws.

Police attempted to arrest the man, who they say resisted.

“The suspect continued to resist, causing minor injuries to one of the officers so the K-9 was released and the K-9 gained control of the suspect’s foot,” the police department said in a statement.

Cellphone video from the incident showed the man on the ground yelling in pain as the police dog bit his foot. The officer held onto the animal by its leash but allowed it to continue attacking the man for about 30 seconds, NBC writes, before finally pulling it away. The man then tried to get up and walk but fell to the ground again, and the officer let the dog keep biting him for another 30 seconds.

The man, who could barely walk after the incident, was taken to a hospital to be treated for his injuries and released. He was not charged with any crimes.

Prior to the FBI’s investigation, protesters gathered outside the Woodson Terrace Police Department on Friday (Sept. 24) to demand the termination of the officers involved. St. Louis County Prosecutor Wesley Bell previously vowed to conduct a “thorough review” of the incident.