Anger erupted on Wednesday when a grand jury brought no charges against Louisville police for the killing of Breonna Taylor during a drug raid gone wrong. Prosecutors in Kentucky said the officers who fired their weapons at Taylor were justified in using force to protect themselves. The only charges brought by the grand jury against the three officers involved were three counts of wanton endangerment against fired officer Brett Hankison for shooting into the homes of Taylor’s neighbors during the raid on the night of 13 March. Hankison was not charged for shooting Taylor. The lawyer Ben Crump said on behalf of Taylor’s family that the grand jury’s decision was “outrageous and offensive”. Taylor, 26, who was Black and worked as an emergency medical technician, was shot at home in March and protests for justice over her death, and against police brutality have spread around the US and beyond. Crowds in Louisville reacted with dismay to the announcements by the Kentucky attorney general, Daniel Cameron, on Wednesday afternoon and marched downtown where protests were ongoing, amid a high police presence. Police were seen arresting a few protesters. John Eligon of the New York Times said on Twitter that after a “loud but peaceful march … police in riot gear confronted protesters and then began pushing them. A chemical agent was used and the officers began arresting protesters, dragging some to the ground.” Footage on social media showed several white men also in the downtown area with guns and wearing body armor, identifying them as some sort of militia. The mayor has ordered a curfew in the Kentucky city for 9 pm. Crowds first gathered in a park in downtown Louisville, where there have been protests every day for months. Someone screamed out in anguish at hearing the news of the charges and people wept, before they began to march. “I’m more saddened than angry,” Monique Lathon, 33, who was there with her young daughter, told the Guardian. David Mour, 59, a lawyer who represents many activists, stood solemnly as the crowd took in the news. “I have had clients indicted for way less,” he said. The civil rights leader Al Sharpton said the charges were “grossly insufficient”, in an interview on MSNBC. Taylor was killed on 13 March by white police officers in Louisville serving a so-called “no-knock warrant” that allowed them to charge into her apartment without warning as part of an investigation into an ex-boyfriend, who was not present. The other two officers with Hankison on the night, Jonathan Mattingly and Miles Cosgrove, fired their weapons inside the apartment after her boyfriend Kenneth Walker fired one shot as they entered. They did not announce themselves as police and he said he believed they were intruders. One officer was shot in the leg and police fired in return. Criminal justice experts had said ahead of the grand jury announcement that a tangled legal doctrine in Kentucky meant a form of self-defense stalemate left questions over what charges a prosecutor could bring against the officers. Cameron, the attorney general, said in a press conference in the state capital, Frankfort, “there is no doubt this is a gut-wrenching” outcome of the case for many. Downtown streets in Louisville, about 50 miles from Frankfort, have been closed off all week as the city awaited the announcement. The Louisville mayor, Greg Fischer, said before the press conference that the city will observe a curfew for at least the next three nights, from 9pm to 6.30am, starting on Wednesday. Protesters had begun marching and chanting as Cameron was still talking, explaining how six police bullets struck Taylor after Mattingly fired six shots, Cosgrove fired 16 shots and Hankison fired 10 shots after entering Taylor’s apartment. Cosgrove is believed to have fired the fatal shot, Cameron said. The officers opened fire after, Mattingly told investigators, they burst into the apartment and saw a man and a woman at the end of the hallway, following which Walker fired one shot that hit Mattingly in the thigh. The police officers then opened fire. Hankison fired from outside the bedroom where Taylor died. Cameron said the loss of Taylor’s life was a tragedy. “I know that not everyone will be satisfied by the charges today,” he said. He added: “I understand as a Black man how painful this is … my heart breaks for the loss of Miss Taylor.” Later, at a press conference at the White House, Donald Trump praised Cameron’s handling of the case, saying he was doing a “fantastic job”, adding: “Justice is … not easy”. He repeated some of Cameron’s remarks earlier in the day, in which he said “justice relies on the facts and the law”. Trump added: “I will be speaking to the governor ... I understand he’s called up the national guard, which I think is a good thing, a positive thing.” Louisville was placed under a state of emergency Tuesday as city officials closed down a more than 25-block perimeter to traffic. Most city administrative buildings and other businesses were boarded up in anticipation of the decision. Protests in Louisville related to Taylor’s death in March have been taking place for more than 100 consecutive days and have been overwhelmingly peaceful. Last week the city of Louisville reached a $12m settlement with Taylor’s family in a civil suit stemming from the shooting. The city has also agreed to policing reforms including a requirement that commanders approve all search warrants before they go to a judge. The California senator and Democratic vice-presidential nominee Kamala Harris has called for the Department of Justice to investigate Taylor’s killing. The progressive congresswoman Alexandria Ocasio-Cortez said the latest news in the case was “weighing really heavy on my heart”. Ocasio-Cortez told a Capitol Hill reporter, “We know that her death is not just the result of one person but the system, structure and department that failed their entire community.”