The city of Memphis is expected to discipline seven additional police officers as it continues investigating Tyre Nichols’ death last month, an official told CNN after a city council meeting Tuesday.

Nichols, 29, was brutally beaten by Memphis Police officers during a Jan. 7 traffic stop, and brought to a hospital where he died three days later. Five police officers were fired soon after the incident, later followed by a handful of emergency responders and a sixth police officer.

Only the first five police officers have been charged with any crimes; they face counts of second-degree murder.

Tuesday’s announcement brings the total number of officers to be disciplined to 13, according to Memphis City Attorney Jennifer Sink. The additional officers are expected to receive a “statement of charges” this week.

“A statement of charges is a document in which the officer is notified of the policy violations that have been identified and then there’s a process by which they are afforded a hearing and then a decision is made,” Sink explained at the city council meeting.

A final round of disciplinary measures is expected to come later this week, Sink said. Administrative hearings are expected to be held next week.

The city is not yet ready to identify all of the officers involved, she added.

Body-camera footage of the Memphis officers’ interaction with Nichols, released late last month, showed how they pursued Nichols on foot when he fled the scene. Once they caught Nichols, the officers deployed a stun gun, pepper spray and an extensive beating, including injuries to his head.

“A lot went wrong on Jan. 7,” Police Chief C. J. Davis said Tuesday.

Davis cited a supervisor shortage and the officers’ “wolf pack mentality” in her comments to Memphis City Council members, defending the training provided to them by the department.

The Associated Press reported Tuesday that the department was forced to lower the bar to joining the force in recent years amid an uptick in crime and difficulty retaining workers.