State investigators said the two officers involved in killing Philando Castile were Jeronimo Yanez and Joseph Kauser, both four-year veterans of the St. Anthony Police Department. Both were put on administrative leave, as is standard.
Yanez approached Castile's car from the driver's side, and Kauser from the passenger side, according to the Minnesota Bureau of Criminal Apprehension. The agency said Yanez opened fire, striking Castile multiple times.
The agency said several videos, including squad car video, have been collected, though St. Anthony officers don't wear body cameras.
A Minnesota prosecutor said Friday he has asked for a "prompt and thorough investigation" following the police killing of a black motorist whose girlfriend streamed the shooting's gruesome aftermath live on Facebook.
Ramsey County Prosecutor John Choi said the video is part of the investigation into Wednesday's shooting of Castile in suburban St. Paul. The school cafeteria supervisor was shot "for no apparent reason" while reaching for his wallet during a traffic stop, after telling the officer he had a gun and a permit to carry it, his girlfriend said in the video.
Choi declined to provide details about the incident. Police also have refused to say what led up to the traffic stop, why Castile was pulled over or why the officer drew his gun.
The bureau did not give the officers' races. Reynolds described the officer who shot Castile as Asian.
The St. Anthony Police Department's 2015 annual report points to Yanez's volunteerism. He gave a tour of the station to a local Cub Scout troop and volunteered with St. Paul's Cinco De Mayo celebration, participating in a parade with other members of the National Latino Police Officers Association.
The previous year's report includes a photo of Yanez solemnly standing guard at a memorial to fallen officers at the state Capitol. Yanez's attorney, Thomas Kelly, didn't return a call seeking comment Thursday.
The U.S. Justice Department, which quickly launched a civil rights investigation into the Baton Rouge shooting, said it would monitor Minnesota's investigation. Dayton said he and other state officials would ask for stronger federal involvement.
At a vigil Thursday evening outside the Montessori school where Castile worked, his mother, Valerie Castile, called her son "an angel." She recalled cautioning him to always comply with police, but she said she never thought she would lose him.
"This has to cease. This has to stop, right now," she told the crowd.
Hundreds of demonstrators braved rain and gathered outside the governor's mansion in St. Paul. The group swelled to over 1,000 for a time late Thursday, as people marched from the school vigil. Dayton waded through the crowd as protesters chanted: "What do we want? Justice! When do we want it? Now!"
President Barack Obama called on law enforcement to root out bias in its ranks, saying the Minnesota and Louisiana shootings were symptoms of a "broader set of racial disparities" in the justice system that aren't being fixed quickly enough.
"When incidents like this occur, there's a big chunk of our fellow citizenry that feels as if it's because of the color of their skin, they are not being treated the same," Obama said several hours before the Dallas shootings. "And that hurts. And that should trouble all of us."
Speaking later, he said America was "horrified" over the Dallas shootings and there was no possible justification for the attacks.