The Justice Department alleged Friday that Minneapolis police have systematically discriminated against Black and Native American people for years and often violated constitutional rights following a sweeping investigation that began after George Floyd was killed.

The two-year probe found that Minneapolis officers used excessive force, including "unjustified deadly force," and violated the rights of people engaged in constitutionally protected speech. The investigation also found that both police and the city discriminated against people with "behavioral health disabilities" when officers are called for help.

"We observed many MPD officers who did their difficult work with professionalism, courage and respect," Attorney General Merrick Garland told a news conference in Minneapolis. "But the patterns and practices we observed made what happened to George Floyd possible."

Garland said officers routinely disregarded the safety of people in their custody, noting numerous situations in which a person in custody complained that they could not breathe, and officers replied with a version of "You can breathe. You're talking right now."

The report included allegations that police "used dangerous techniques and weapons against people who committed at most a petty offense and sometimes no offense at all." Officers "used force to punish people who made officers angry or criticized the police."

Police also "patrolled neighborhoods differently based on their racial composition and discriminated based on race when searching, handcuffing or using force against people during stops," the report said.

As a result of the investigation, the city and the police department agreed to a deal known as a federal consent decree, which will require reforms to be overseen by an independent monitor and approved by a federal judge. That arrangement is similar to reform efforts in Seattle, New Orleans, Baltimore and Ferguson, Missouri.

Police Chief Brian O'Hara, who led Newark, New Jersey, police through a consent decree, said the Minneapolis department was committed to creating "the kind of police department that every Minneapolis resident deserves."

Mayor Jacob Frey acknowledged the work that lay ahead.

"We understand that change is non-negotiable," Frey said. "Progress can be painful, and the obstacles can be great. But we haven't let up in the three years since the murder of George Floyd."

The investigation was launched in April 2021, a day after former officer Derek Chauvin, who is white, was convicted of murder and manslaughter in the May 25, 2020, killing of Floyd, who was Black.

Floyd repeatedly said he couldn't breathe before going limp as Chauvin knelt on his neck for 9 1/2 minutes. The killing was recorded by a bystander and sparked months of mass protests as part of a broader national reckoning over racial injustice.

Garland also said the report found that Chauvin used excessive force on other people on multiple occasions, and fellow officers stood by and did not stop him.

The report found that the city sent officers to behavioral health-related 911 calls, "even when a law enforcement response was not appropriate or necessary, sometimes with tragic results. These actions put MPD officers and the Minneapolis community at risk."

The findings were based on reviews of documents and incident files; observation of body-worn camera videos; data provided by the city and police; and ride-alongs and conversations with officers, residents and others, the report says.

Federal investigators acknowledged that the city and Minneapolis police have already begun reforms.

The report noted that police are now prohibited from using neck restraints like the one Chauvin used in killing Floyd. Officers are no longer allowed to use some crowd control weapons without permission from the chief. And "no-knock" warrants were banned after the 2022 death of Amir Locke.

The city also has launched a "promising" behavioral health response program in which trained mental health professionals respond to some calls rather than police.

The Justice Department is not alone in its findings of problems.

A similar investigation by the Minnesota Department of Human Rights led to a "court-enforceable settlement agreement" to address the long list of problems identified in the report, with input from residents, officers, city staff and others. Frey and state Human Rights Commissioner Rebecca Lucero signed the agreement in March.

The state investigation, which concluded in April 2022, found "significant racial disparities with respect to officers' use of force, traffic stops, searches, citations, and arrests." And it criticized "an organizational culture where some officers and supervisors use racist, misogynistic, and disrespectful language with impunity."

Lucero said the legally binding agreement requires the city and the police department to make "transformational changes" to fix the organizational culture of the force, noting it could serve as a model for how cities, police departments and community members elsewhere work to stop race-based policing.

The report recommends 28 "remedial" steps to improve policing as a prelude to the consent decree. Garland said the steps "provide a starting framework to improve public safety, build community trust and comply with the constitution and federal law."

The mayor said city leaders want a single monitor to oversee both the federal plan and the state agreement to avoid having "two different determinations of whether compliance has been met or not. That's not a way to get to clear and objective success."

Several police departments in other cities operate under consent decrees for alleged civil rights violations. A consent decree requires agencies to meet specific goals before federal oversight is removed, a process that often takes many years at a cost of millions of dollars.

Floyd, 46, was arrested on suspicion of passing a counterfeit $20 bill for a pack of cigarettes at a corner market. He struggled with police when they tried to put him in a squad car, and though he was already handcuffed, they forced him on the ground.

Chauvin was sentenced to 22 1/2 years for murder. He also pleaded guilty to a federal charge of violating Floyd's civil rights and was sentenced to 21 years in that case. He is serving the sentences concurrently in Tucson, Arizona.