MINNEAPOLIS'Protesters demanding action over the death of 46-year-old George Floyd took over the Minneapolis Police Department's Third Precinct late Thursday and set the building ablaze.Video from the scene showed demonstrators chanting 'I can't breathe' and cheering as the building was breached, with alarms blaring in the background.'This is 400 years of anger,' one protester, Justin Galbraith, told The Daily Beast as the flames sent smoke up into the sky.Others in the crowd echoed that sentiment. 'There are so many innocent lives lost by the police. We protest peacefully and there is no accountability. So this happens,' demonstrator Cecilia Zwak said. The takeover appeared to mark a turning point in the protests that kicked into a new gear nationwide Thursday, as a bumbling press conference by confused prosecutors risked inviting further rage and violence. From New York City to Denver to St. Paul, activists massed in the face of a pandemic to call out what they saw as the wanton killing of Floyd, an unarmed black man, by a Minneapolis cop on Monday. Dozens of arrests were reported by late Thursday afternoon in Manhattan's Union Square, at least one protester in Minneapolis was said to be stabbed, and along with horrifying video footage of a car slamming into a protester in Denver, gunfire was reported at the state capitol there.After midnight, the president threatened a violent response. 'These THUGS are dishonoring the memory of George Floyd, and I won't let that happen,' he wrote on Twitter. Trump added, 'When the looting starts, the shooting starts,' quoting the controversial Miami Police chief Walter Headley who became infamous in the 1960s for his aggressive tactics in putting down black youths he claimed were taking advantage of civil rights legislation.At one point in Minneapolis early Thursday evening, a brawl broke out between members of a small group of protesters. Anthony Thornton, 32, of North Minneapolis, said he chased down the alleged assailant.'I saw him in the fight across the street and saw him run away. People were yelling that he stabbed someone,' Thornton told The Daily Beast, while brandishing a pistol. 'I jumped in my Jeep and chased him across the parking lot, pointed my gun at him, and told him to stop. He stopped and walked here with me peacefully.''I've been here for three days. I'm a protester,' Thornton added. 'Things are not supposed to go down like this. I'm just making sure things stop.'The question'as cops continued to use tear gas, protesters threw eggs at cop cars, and vandalism and looting reportedly percolated in the Twin Cities'was how authorities would respond to escalating chaos in the hours ahead. Minnesota Gov. Tim Walz officially activated the National Guard earlier in the day, raising the prospect of a military-style occupation of swaths of a city with a long history of police violence.Meanwhile, a longtime friend of George Floyd, former NBA star Stephen Jackson, appealed to protesters to stand up for Floyd the 'right way.' In an interview with MSNBC, Jackson said his slain friend 'wouldn't want it to be this way.''He wouldn't have wanted people to be tearing stuff down, and people getting hurt,' he said. 'He wouldn't want businesses and people to suffer."The more immediate concern for activists, however, may have been county and federal prosecutors calling a press conference Thursday afternoon to announce nothing'except, well, that they thought the case was complicated.'There is other evidence that does not support a criminal charge,' Hennepin County Attorney Mike Freeman said of calls to bring charges against the white police officer in Floyd's death. The officer was caught on video kneeling on Floyd's neck for at least seven minutes while Floyd pleaded and warned that he couldn't breathe. He was without a pulse when placed in an ambulance a short time later. U.S. Attorney Erica MacDonald went so far as to apologize for summoning the press for no reason, while Freeman said he wanted to avoid potentially prematurely filing aggressive charges only to see them go down at trial.He specifically cited the failed prosecution of police over the death of Freddie Gray in Baltimore in 2015.Demonstrators who faced down tear gas projectiles in Minneapolis on Thursday were less concerned with legal precedents and more determined to have the case seen for the outrage that they say it is.'George Floyd was killed over nothing. It was a modern day lynching. We have no voice,' demonstrator Josh Estes told The Daily Beast.'I feel it's necessary. Otherwise, nothing is going to change,' Summer Bond, 22, told The Daily Beast of sprawling destruction that included a police vehicle. 'I do feel bad for the businesses. But the squad car' The station' Not at all.'In Denver, a person with a scarf around his face took a bat to two official state vehicles, and rocks were hurled at first-floor building. Police there also used tear gas on demonstrators around 8:30 p.m.Reports of gunfire sent the city's State Capitol building into lockdown a few hours earlier, according to the Colorado State Patrol. No injuries were immediately reported, but protests continued apace.'This only makes me more resolved. We have more work to do,' Leslie Herod, a state legislator, told The Daily Beast while sheltering in place.Read more at The Daily Beast.Get our top stories in your inbox every day. Sign up now!Daily Beast Membership: Beast Inside goes deeper on the stories that matter to you. Learn more. Click here to read full news..