WASHINGTON — The police department in Louisville, Ky., engaged in a yearslong pattern of discriminatory law enforcement practices, the Justice Department said on Wednesday after conducting a two-year investigation prompted by the fatal shooting of Breonna Taylor by the police in 2020.
Attorney General Merrick B. Garland, appearing in Louisville alongside the city’s mayor and acting police chief, announced an agreement to overhaul policing practices he said had led to systemic discrimination against Black people, including Ms. Taylor. Ms. Taylor, a Black medical worker, was shot and killed by police officers assigned to a drug enforcement unit in March 2020 during a botched raid of her apartment.
In a damning 90-page report, investigators painted a grim portrait of the Louisville Metro Police Department, detailing a variety of serious abuses, including excessive force; searches based on invalid and so-called no-knock warrants; unlawful car stops, detentions and harassment of people during street sweeps; and broad patterns of discrimination against Black people and people with behavioral health problems.
“The L.M.P.D.’s conduct has undermined its public safety mission and strained its relationship with the community it is meant to protect and serve,” Mr. Garland said.
The Justice Department’s findings, he said, were succinctly captured by an unnamed Louisville police leader interviewed during the investigation:
“Breonna Taylor was a symptom of problems we have had for years.”
Justice Department investigators also found widespread problems in the way the police handled investigations of domestic violence and sexual assault cases, including allegations of sexual misconduct or domestic violence against law enforcement officers.
Mr. Garland said that his investigators also uncovered instances of blatant racism against Black Louisville residents, including the disproportionate use of traffic stops in Black neighborhoods — and even the use of racist epithets like “monkey,” “animal” and “boy.”
Kristen Clarke, the assistant attorney general for civil rights, said that the targeting of Black people for traffic stops and searches turned conventional law enforcement practices into “weapons of oppression, submission and fear.”
The Louisville investigation is one of several so-called pattern or practice investigations into potentially discriminatory policing around the country that have been opened under Mr. Garland.
The investigation and report, which are likely to lead to a consent decree by both parties, are separate from the federal criminal investigation into the conduct of the members of a drug enforcement unit who broke down the door to Ms. Taylor’s apartment, killing her as they engaged in a shootout with her boyfriend.
Some of the reforms outlined by Mr. Garland have already been undertaken. After Ms. Taylor’s death, the department banned “no-knock” warrants, which allowed officers to break into a residence without warning. Officials have also expanded their use of counseling and training for officers and appointed an inspector general to review the department’s practices.
“We will not make excuses, we will make changes,” said Mayor Craig Greenberg of Louisville, a Democrat who took office in January.
Mr. Greenberg vowed to embrace an overhaul of the department’s practices.
He called the abuses outlined in the report “a betrayal of the integrity and professionalism that the overwhelming majority of our officers bring to their job every day and every night.”