When three former Minneapolis police officers emerged from a hearing in a downtown courthouse Friday afternoon, hundreds of protesters, who minutes earlier had been line dancing in the street, instantly transformed into an aggressive mob, screaming "Murderer!" as they followed two of the men to their parked vehicle.

The protesters swarmed around a truck as former officer Thomas Lane got into the front passenger seat and his one-time partner, J. Alexander Kueng, sat behind the driver, his attorney, Thomas Plunkett. The ex-officers did not react or engage with the crowd as they walked through a gauntlet of protesters who extended their middle fingers and yelled at the men.

Earl Gray, Lane's attorney, climbed into the truck behind his client. Plunkett managed to ease the truck out of a metered spot without harming anyone even as protesters enveloped the vehicle and pounded on it.

It was an extraordinarily unsettling midday scene on Marquette Avenue outside Hennepin County's Family Justice Center, a building where judges normally work out divorce settlements, paternity disputes and child custody agreements. On Friday, however, one courtroom was the site of a pretrial hearing for the state's case against the four former officers charged in the death of George Floyd outside Cup Foods in south Minneapolis on May 25.

Kueng, Lane and ex-officer Tou Thao each are charged with aiding and abetting murder and manslaughter in Floyd's killing. Former officer Derek Chauvin, the only one who hasn't posted bond and remains in custody, faces the most serious charges of second-degree unintentional murder, third-degree murder and second-degree manslaughter.

The protesters filled the streets around the building long before the 9 a.m. start of the 3 ½-hour hearing, setting up an impressive sound system with giant speakers and a microphone for music and a series of focused, emotional speeches that lasted four hours.

The group swelled to a peak of several hundred as the hearing took place inside and out of sight. The crowd chanted, "Indict, convict, send those killer cops to jail! The whole damn system is guilty as hell!"

Elizer Darris of Minneapolis took off his face mask bearing the name of Breonna Taylor, a Black woman killed by police in Kentucky, and encouraged others to keep up the pressure beyond Friday's hearing. "This isn't a moment; it's a movement," Darris said.

His message, like that of many of those on the street Friday, was that the trial must be held in Minneapolis — not moved elsewhere in the state as defense lawyers have sought. "They murdered him here," Darris said. "We demand justice. This is our pain," he added. "We will not let you take this dirty laundry to St. Cloud."

Protest organizers monitored the perimeter of the event, some carrying first-aid supplies, water and food. Initially, several dozen people lay silently on the ground for eight minutes and 46 seconds — the amount of time Floyd was pinned beneath Chauvin's knee before paramedics swept away his inert body.

As the protesters rose, Marvin Gaye's voice rang out through the speakers, "Mother, mother, There's too many of you crying," — the first verse from, "What's Going On," the late singer's 1971 plea for peace.

Attendance inside the hearing was limited because of the COVID-19 pandemic, and protesters could neither see nor hear what was happening. But the message outside was clear.

"We have to stop the police from killing us with impunity," said Jae Yates, who spoke several times.

Protesters also delivered messages with their signs: "No clemency for killer kkkops," and "Recall Freeman," a reference to Hennepin County Attorney Mike Freeman, whose office has been criticized for its work on this case and earlier police killings.

One woman carried a sign in the image of a blue Minneapolis police logo reconfigured to read, "Murderous City of Lakes Police." Another sign read, "If you think they did it by the book, then we'll have to burn every page."

The crowd thinned as the morning wore on. Those remaining began dancing the Cupid Shuffle and the Electric Slide.

When the hearing wrapped up and reporters gathered in a fenced pen awaiting the lawyers, the protesters played N.W.A.'s profane anti-police anthem from its 1988 "Straight Outta Compton" album.

Then the three former officers emerged. Thao and his lawyer, Robert Paule, walked down the street without much notice along with Chauvin's lawyer, Eric Nelson.

But Lane, 6-foot-4, towered above the crowd and instantly caught the attention of protesters, who converged on him and his silver-haired lawyer as they walked with Kueng and Plunkett, who tends to wear distinctive hats.

Chauvin was taken out the back door in an orange jumpsuit and protective vest with his hands cuffed in front of him; heavy security kept onlookers at a distance.

As the defendants pulled away, the crowd wandered back across the street to listen to Benjamin Crump, a well-known civil rights lawyer representing the Floyd family.

"We got your back," the protesters shouted.

Crump responded, "The whole world is watching."