The US justice department announced on Wednesday that it is launching a sweeping investigation into policing practices in Minneapolis, less than a day after a white former officer was convicted of murdering George Floyd, a 46-year-old Black man, there. The investigation will examine the use of force by police officers, including force used during protests, and whether Minneapolis police engage in discriminatory practices, the US attorney general, Merrick Garland, said in Washington DC on Wednesday morning. “The justice department has opened a civil investigation to determine whether the Minneapolis police department has engaged in a pattern and practice of unconstitutional or unlawful policing,” Garland said. The federal government will also examine the handling of misconduct allegations against police and law enforcement’s treatment of people with behavioral health issues – and justice officials will also assess the department’s current systems of accountability, the attorney general added. Garland’s announcement came less than a day after the former Minneapolis police officer Derek Chauvin was found guilty of all three charges related to murder and manslaughter in the killing of Floyd in the Minnesota city last May. When bystander video of Chauvin kneeling on Floyd’s neck as he was pinned to the street, crying out that he could not breathe, reached the internet it set off a wave of protests in Minneapolis and neighboring St Paul and across the country and internationally. The reckoning on police brutality and racial injustice was part of a huge resurgence of the Black Lives Matter movement and turned into the biggest civil rights uprising in the US since the 1960s. Protests went on not just through the summer but right up until the trial of Chauvin opened on 29 March in a heavily fortified court house in downtown Minneapolis. After three weeks, the jury retired and deliberated for about 10 hours before returning a unanimous verdict that Chauvin murdered Floyd. Chauvin was immediately taken into custody, leaving the courtroom in handcuffs. He will be sentenced in two months’ time. The most serious charge against him carries a maximum sentence of 40 years. The swift verdict generated celebrations in Minneapolis and a wave of relief across the country, where cities had been bracing for mass unrest if Chauvin had been acquitted or even if he had been convicted only of manslaughter. Joe Biden and Vice-President Kamala Harris addressed the nation from the White House shortly after the verdict was announced on Tuesday afternoon, saying it was just one step towards fairer policing in America. Harris, America’s first vice-president who is female and a person of color, said: “A measure of justice is not the same as equal justice … here is the truth about racial injustice, it’s not just a Black American problem or a people of color problem, its a problem for every American.” Biden spoke of systemic racism as a stain on the nation and called Chauvin’s conviction “a step forward”. “Protests unified people of every race and generation in peace and with purpose to say enough,” Biden said. “Enough. Enough of the senseless killings … The guilty verdict does not bring back George [Floyd]. George’s legacy will not be just about his death, but about what we must do in his memory.” The president also called for progress on a key piece of legislation promoting police reforms, the George Floyd Justice in Policing Act 2020, which is stuck in the US Senate without agreement on the way forward. The justice department was already investigating whether Chauvin and the three other officers involved in Floyd’s death violated his civil rights. The three other officers are due to stand trial together in August, charged with aiding and abetting manslaughter. On Wednesday, Garland said: “Yesterday’s verdict in the state criminal trial does not address potentially systemic policing issues in Minneapolis.” Garland said a public report would be issued, if the government finds a pattern or practice of unconstitutional policing. The Biden administration could also bring a lawsuit against the police department, which in the past have typically ended in settlement agreements or so-called consent decrees to force changes. The Minneapolis police department is also being investigated by the Minnesota department of human rights, which is looking into the department’s policies and practices over the last decade to see if it engaged in systemic discriminatory practices. Minneapolis’s mayor, Jacob Frey, said city officials “welcome the investigation as an opportunity to continue working toward deep change and accountability in the Minneapolis police department”. The city council also issued a statement supporting the investigation, saying its work had been constrained by local laws and that it welcomed “new tools to pursue transformational, structural changes to how the city provides for public safety”. More than 200 people have suffered police-involved deaths in Minnesota in the last 20 years, a database compiled by the Minneapolis Star Tribune calculated. While only 7% of Minnesotans are Black they accounted for 26% of those deaths. Two weeks after Floyd’s killing, a majority on Minneapolis city council members pledged to “begin the process of ending” the police department, saying it “cannot be reformed” and would be replaced with a new system of public safety. It was the kind of change that the protests were about: calls to end brutal, racist policing and entrenched racism more broadly, and to defund law enforcement began sweeping the US. But the Minneapolis pledge ran into legal barriers at city and state level, as well as pushback from some police reform activists who said a proposed amendment to the city’s charter to remove the police department was too vague and didn’t reflect feedback from the wider community.