As events in north Minneapolis progressed in the week since the fatal police shooting of Jamar Clark, a 24-year-old black man, individual voices warned of a danger.
People allied with the Black Lives Matter movement alleged that white supremacists had been lurking around the encampment of protesters outside the 4th Precinct station of the Minneapolis Police Department.
But as events unfolded Tuesday, there was no way to know what was going on when a confrontation near the 4th Precinct erupted in gunfire Monday night.
Macalester Professor Emeritus Mahmoud El-Kati had addressed the crowd of protesters Thursday evening. "White supremacy is on the run," he said, and added a warning:
"Let me say this: There's a principle in physics, you know, called action and reaction. There's an action and a reaction and a reaction to the reaction. They are going to react to this, and it's not going to be pretty. So bear up."
A video of unknown origin and authenticity circulated online Friday, purporting to show two white men in a car, displaying a pistol they said was "locked and loaded," claiming they were en route to the Minneapolis protest. They signed off with the words "Stay white."
Nekima Levy-Pounds, president of the Minneapolis NAACP, said after the shootings that "for the last several days, white supremacist groups have been threatening to come here and threatening to try to rile up protesters by throwing rocks and Molotov cocktails, and some said that they would be armed. And so we've tried to take precautions by looking for people who look suspicious."
But for all of those warnings, there was no way of knowing whether the shootings Monday night were indeed the work of white supremacists. Witnesses described the alleged shooters as white, but there was no hard information to support a conclusion that seemed obvious to the protesters and their allies.
"Tonight they actually acted upon their threats," Levy-Pounds said after the shootings.
The incident came nine days after Jamar Clark's shooting. Police said Clark had been shot while trying to wrest control of an officer's gun; members of Black Lives Matter insisted that he had been handcuffed and unarmed at the time he was shot.
In the days since then, protesters occupied and then were ejected from the foyer of the 4th Precinct. Surveillance cameras and police cars sustained damage reckoned in the tens of thousands of dollars. A camp grew up outside the precinct, and scores of protesters were arrested for blocking traffic on Interstate Hwy. 94.
All the while, leaders of Black Lives Matter Minneapolis and the Minneapolis NAACP pressed their demand for the release of video being held by federal and state investigators. They also called for a federal investigation, which is underway, and for placing the Minneapolis police under federal control.
Authorities have refused to release the video, taken from the rear of an ambulance, on the grounds that it might taint the investigation. Gov. Mark Dayton announced Monday that he had watched the video, and that it provided no evidence to support either version of events.
At the same time, Dayton recognized that tensions were growing, calling the dispute over Clark's death "a very, very volatile situation."
"I want to know everything I possibly can ... to make the best informed decision I possibly can to protect public safety," he said.
Monday's shootings left the public's safety a decidedly open question.
Police moved quickly to investigate the shootings, although people in the crowd outside the station said they had been slow in responding to the incident. By Tuesday evening, police said they had three men in custody and released a fourth, after they'd determined he was not near the precinct at the time of the shooting.