Two officers have been shot as thousands of people protest in the US city of Louisville after a grand jury decided no-one would be charged with the death of Breonna Taylor.
Ms Taylor, 26, a hospital worker, was shot multiple times as officers stormed her home on 13 March.
Brett Hankison has been charged, not with Ms Taylor’s death, but with “wanton endangerment” for firing into a neighbour’s apartment in Louisville.
Two other officers face no charges.
Louisville Police Chief Robert Schroeder said the officers conditions are not life-threatening.
He added that a suspect is in custody.
A state of emergency has been declared in Louisville and the National Guard have also been deployed.
Mayor Greg Fischer has set a 21:00-06:30 (01:00-10:30 GMT) curfew in the city for three days. He earlier said he had declared a state of emergency “due to the potential for civil unrest”.
“We know that the answer to violence is never violence and we are thinking about those two officers and their families tonight. So I’m asking everybody: please, go home. Go home tonight,” he said.
Under Kentucky law, someone is guilty of wanton endangerment if they commit an act that shows “an extreme indifference to the value of human life”.
This lowest-level felony offence can come with a five-year sentence for each count. Brett Hankison was charged on three counts.
Ms Taylor’s relatives and activists for whom her death has become a rallying cry had been calling for the three officers, who are all white, to be charged with murder or manslaughter.
But this was rejected by a grand jury that reviewed the evidence.
On Wednesday, Judge Annie O’Connell announced the charges that had been brought against Mr Hankison.
Kentucky Attorney General Mr Cameron then held a news conference in which he expanded on the decision. “This is a gut-wrenching emotional case,” he said.
“There is nothing I can offer them today to take away the grief and heartache as a result of losing a child, a niece, a sister and a friend,” he added in a message to Ms Taylor’s family.
Mr Cameron said a ballistics report had found that six bullets struck Ms Taylor, but only one was fatal.
That analysis concluded that Detective Myles Cosgrove had fired the shot that killed Ms Taylor.
The attorney general said it was not clear if Mr Hankison’s shots had hit Ms Taylor, but they had hit a neighbouring apartment.
The top prosecutor said the other two officers – Jonathan Mattingly and Mr Cosgrove – had been “justified to protect themselves and the justification bars us from pursuing criminal charges”.
Mr Cameron, a Republican who is the state’s first black attorney general, added: “If we simply act on emotion or outrage, there is no justice.
“Mob justice is not justice. Justice sought by violence is not justice. It just becomes revenge.”
He added that the FBI was still investigating potential violations of federal law in the case.