A grand jury has charged one police officer over the raid which resulted in the fatal shooting of Breonna Taylor at her home in the US state of Kentucky.
Ms Taylor, 26, a hospital emergency room technician, was shot multiple times during the raid on 13 March.
Her death has become a rallying cry for anti-racism protesters, who called for the three officers involved to be arrested and charged.
Officials earlier agreed to pay her family $12m (£9.3m) in a settlement.
Brett Hankison has been charged with three counts of “wanton endangerment” over shots that were fired into a neighbouring apartment.
He was fired from the Louisville Metro Police Department in June after investigators found he had “wantonly and blindly fired 10 rounds” into the apartment, according to his termination letter.
The other two officers who discharged their weapons that night – Jonathan Mattingly and Myles Cosgrove – have not been charged.
A state of emergency was declared in Louisville ahead of the announcement on Wednesday.
Mayor Greg Fischer also set a 21:00-06:30 curfew in the city that will remain in place for the next 72 hours. He earlier said he had declared a state of emergency “due to the potential for civil unrest”.
Demonstrations over Ms Taylor’s death have been held in the city for more than 100 consecutive days. Police have closed traffic on certain streets where protests have been prevalent and barricades have been erected around the city centre.
What happened to Ms Taylor?
Ms Taylor was at home in Louisville on 13 March when police officers entered her apartment shortly after midnight, her family says.
Narcotics officers raided her home and used a battering ram to take her front door off its hinges. No drugs were found on her property and Ms Taylor had no criminal record.
Police were acting on a controversial type of search warrant – known as a “no-knock” warrant – that allows police to enter a home without warning. Police claim they knocked and announced themselves before entering, but Ms Taylor’s family and a neighbour have disputed this.
At the time, Ms Taylor was in bed with her boyfriend Kenneth Walker, a licensed gun owner, according to her family. Hearing the commotion, Mr Walker believed people were trying to break into the apartment and he later told police he fired one shot of his pistol.
Officials say Mr Walker’s bullet struck a police officer, Jonathan Mattingly, in the leg – an injury for which he later required surgery.
Mr Mattingly and two other officers, Brett Hankison and Myles Cosgrove, returned fire and shot more than 20 rounds. Mr Walker wasn’t wounded but Ms Taylor was hit multiple times and died in the hallway of her apartment, lawyers for her family said.
The subsequent police report contained numerous errors, including listing Ms Taylor’s injuries as “none” and saying no force was used to enter, when a battering ram had been used.
Mr Walker was initially charged with attempted murder and assault of a police officer, but the case against him was dropped in May amid national scrutiny of the case.
What about the officers?
While Mr Hankinson was fired from the force in June, Mr Mattingly and Mr Cosgrove were reassigned to administrative duties.
The Louisville Courier-Journal has reported that six officers are under internal police review for their role in the shooting.
Mr Mattingly wrote an email on Saturday to more than 1,000 colleagues in which he criticised city leaders and protesters.
“Regardless of the outcome today or Wednesday, I know we did the legal, moral and ethical thing that night,” he wrote in the message, which was published by media outlets on Tuesday.
“It’s sad how the good guys are demonised, and the criminals are canonised.”
“Your civil rights mean nothing,” he added, “but the criminal has total autonomy.”