A police officer who fatally shot Rayshard Brooks, a black man killed last week in Atlanta, will be charged with murder and assault, officials say.
The other officer involved plans to testify as a witness in the case, the Fulton County District Attorney said in a news conference on Wednesday.
The decision comes in the wake of nationwide protests over the deaths of black Americans in police custody.
Lawmakers in Washington are currently debating new police reform laws.
Garrett Rolfe, who has already been fired from the Atlanta police force, will face 11 charges related to Mr Brooks' death. If convicted of the charges, he could face the death penalty.
Officer Devin Brosnan, who was also present for the arrest, will be charged with assault for standing on Mr Brooks' shoulder as he lay dying.
Fulton County District Attorney Paul Howard said that this was the ninth time that an Atlanta police officer had been prosecuted for homicide.
He added that he believed it was the first time a police officer had offered to testify against a member of his unit.
Mr Brooks failed a field sobriety test on 12 June after he was found asleep inside his car, blocking a drive-through lane at a Wendy's restaurant.
For over 40 minutes, video shows him complying with officers as he consented to a weapons search and provided them with his identification details.
District Attorney Howard said that eight videos from the scene showed that Mr Brooks "displayed no aggressive behaviour during the 41 minutes and 17 seconds" that he was questioned, and posed no physical risk to the officers in that time.
However, as officers tried to handcuff him, he began struggling. Mr Brooks punched an officer, grabbing one of their Tasers and turning back to fire it at them as he fled.
Mr Brooks suffered two gunshots to the back that caused organ injuries and blood loss. One police bullet also hit a witness' vehicle, nearly killing the driver, investigators say.
Garrett Rolfe, who fired the fatal shot, has already been sacked from the Atlanta police force. Officer Devin Brosnan, who was also present for the arrest, has been placed on administrative leave.
Mr Brosnan has become a state witness, and plans to testify in the case, according to Mr Howard.
Video shows Mr Rolfe saying "I got him". For two minutes after Mr Read More – Source