THE United States Justice Department has launched a civil investigation into the police force whose officers shot dead unarmed black woman Breonna Taylor last year, Attorney General Merrick Garland said on Monday.

The probe into Louisville police will also focus on the Louisville-Jefferson County government, he said, and will assess whether the police routinely use unreasonable force, including on protesters.

A similar review is under way of Minneapolis police, which was begun soon after former officer Derek Chauvin was found guilty of the murder of unarmed black man George Floyd.

Mr Garland said the investigation would also look at whether Louisville police regularly engage in racially discriminatory practices or deny access to public services for people with disabilities.

“Those investigations and recommendations and actions that ensue do not only protect individuals’ civil rights, they also assist police departments in developing measures to increase transparency and accountability,” he said.

Ms Taylor was shot dead during a botched raid on her home in March last year as police forced their way into her apartment tackling alleged drug-dealing operations.

Only one of the three officers involved in the shooting has faced charges. A number of jurors in the initial investigation accused the Kentucky Attorney General Daniel Cameron and the police of a cover-up.

Louisville police chief Erika Shields acknowledged her department had to “rebuild our product.”

“What I will be pushing for is more resources, more training … More tools other than lethal force,” she said.

Ms Shields was appointed to the post earlier this year after she was forced to resign as Atlanta police chief last June following the fatal police shooting of an African-American man, Rayshard Brooks.