The Justice Department is opening a sweeping probe into policing in Louisville, Kentucky, following the death of Breonna Taylor, who was shot by officers during a raid at her home.
It is the second such sweeping probe into a law enforcement agency announced by the Biden administration in a week.
Ms Taylor, 26, who was an emergency medical technician and had been studying to become a nurse, was roused from sleep by police who came through the door using a battering ram in March 2020.
Her boyfriend, Kenneth Walker, fired once. A no-knock warrant was approved as part of a narcotics investigation. No drugs were found at her home.
The investigation is into the Louisville-Jefferson County Metro Government and the Louisville Metro Police Department.
It is known as a “pattern or practice” — examining whether there is a pattern or practice of unconstitutional or unlawful policing — and will be a more sweeping review of the entire police department.
It will specifically focus on whether the Louisville Metro Police Department engages in a pattern of unreasonable force, including against people engaging in peaceful activities, and will also examine whether the police department conducts unconstitutional stops, searches and seizures and whether the department illegally executes search warrants, Attorney General Merrick Garland.
The probe will also look at the training that officers receive, the system in place to hold officers accountable and “assess whether LMPD engages in discriminatory conduct on the basis of race,” among other things, he said.
Mr Garland last week announced a probe into the tactics of the police in Minneapolis following the death of George Floyd.
The attorney general has said there is not yet equal justice under the law and promised to bring a critical eye to racism and legal issues when he took the job. Few such investigations were opened during the Trump administration.
Former Minneapolis police officer Derek Chauvin was convicted last week of murder in Mr Floyd’s death, but no-one has been charged in Ms Taylor’s, though her case, too fuelled protests against police brutality and systemic racism.
Her death prompted a national debate about the use of so-called “no knock” search warrants, which allow officers to enter a home without waiting and announcing their presence.
The warrants are generally used in drug cases and other sensitive investigations where police believe a suspect might be likely to destroy evidence. But there has been growing criticism in recent years that the warrants are overused and abused.
Prosecutors will speak with community leaders, residents and police officials as part of the Louisville probe and will release a public report, if a pattern or practice of unconstitutional conduct is discovered, Mr Garland said.
He noted that the department has implemented some changes after a settlement with Ms Taylor’s family and said the Justice Department’s investigation would take those into account.
“It is clear that the public officials in Minneapolis and Louisville, including those in law enforcement, recognize the importance and urgency of our efforts,” Mr Garland said.
Kentucky’s lawmakers passed a partial ban on no-knock warrants last month. The measure would only allow no-knock warrants to be issued if there was “clear and convincing evidence” that the “crime alleged is a crime that would qualify a person, if convicted, as a violent offender.”
Warrants also would have to be executed between 6am and 10pm.