Minneapolis mayor receives assistance from the National Guard as protests over George Floyd's death turn deadly and buildings go up in flames

• Minneapolis has been in the grips of violent protests since George Floyd died in police custody, saying, "Please, I can't breathe."
• Mayor Jacob Frey has requested help from the National Guard to address the protests, he told local news organizations.
• The Justice Department on Thursday promised a "robust criminal investigation into the circumstances surrounding" the 46-year-old black man's death.
• Federal criminal charges are being considered as calls mount for the four police officers involved in the deadly encounter to be jailed. They've all been fired from their jobs.

Minneapolis Mayor Jacob Frey asked Minnesota Gov. Tim Walz's office to provide help from state troopers and the National Guard as protests in the wake of George Floyd's death turn increasingly violent.

He received that assistance on Thursday evening when Walz signed an executive order calling up National Guard troops "to help protect Minnesotans' safety and maintain peace in the wake of George Floyd's death."

Floyd died after Minneapolis police arrested him on Memorial Day. In the days following his death, outrage has prompted demonstrators to chant for justice in Memphis and to block freeways in California.

In Minneapolis — the site of the 46-year-old black man's death, where he was handcuffed, pinned under the knee of a white police officer, and gasped, "Please, I can't breathe" — protests have devolved into violence and chaos.

"While many Minnesotans are taking extensive safety precautions while exercising their right to protest, the demonstration last night became incredibly unsafe for all involved," Walz said in a statement. "The purpose of the National Guard is to protect people, to protect people safely demonstrating, and to protect small business owners."

Frey also pleaded with residents as protestors ravaged parts of the city Wednesday, urging them to not "let tragedy beget more tragedy," according to Star Tribune reporter, Liz Navratil.

"I cannot risk the safety of innocent people and so that is what I've been sworn to uphold and that is what I am dedicated to do," Frey told NBC affiliate, KARE 11. "We can have both things. We can have peaceful demonstrations, but I also have to ensure the safety of everyone in the city."

Frey quickly condemned the officers who took Floyd into custody after a video circulated of Derek Chauvin, the white police officer, kneeling in Floyd's neck. He's called on Hennepin County Attorney Mike Freeman to pursue criminal charges against Chauvin.

Four officers involved in the arrest, including Chauvin, have already been fired from the police force.

The protests grew in the nights following Floyd's death

On Tuesday and Wednesday night, Minneapolis took to the streets. People have looted a Target store, set fire to buildings, damaged businesses, and clashed with riot gear-clad police, who responded with tear gas, rubber bullets, and flash bombs. On Wednesday, a man was shot dead outside a pawn shop.

"I'm imploring our city, imploring our community, imploring every one of us to keep the peace. Let's honor George Floyd's memory," Frey told KARE 11.

A group of protestors also gathered outside Chauvin's home Wednesday night, NBC News reported. That group stayed peaceful.

At a news conference on Thursday morning, Minneapolis police spokesman John Elder described "a different night of protesting than it was just the night before."

Police Chief Medaria Arradondo also pleaded for peace as the deadly encounter is investigated.

"Justice historically has never come to fruition through some of the acts that we're seeing tonight, whether it's the looting, whether it's the damage of property and other things," Arradondo told KMSP-TV.

President Donald Trump also weighed in on Wednesday, tweeting his condolences to Floyd's family and asserting. He also took credit for the involvement of the FBI and the Department of Justice, even though local authorities said days earlier that they were already involved in the case.

U.S. Attorney Erica McDonald and FBI Special Agent Rainer Drolshagen followed Trump's comment with a statement on Thursday, promising a "robust criminal investigation into the circumstances surrounding" Floyd's death. The Justice Department views this as a "top priority," the statement said.

"The federal investigation will determine whether the actions by the involved former Minneapolis Police Department officers violated federal law," she said in the statement. "It is a violation of federal law for an individual acting under color of law to willfully deprive another person of any right protected by the Constitution or laws of the United States."

McDonald and Drolshagen asked people with information relevant to the case to come forward and noted that both evidence and witness testimony will be considered when determining if federal criminal charges are warranted.

The state's Bureau of Criminal Apprehension and the Hennepin County Attorney's Office are also investigating Floyd's death as calls mount for the four officers involved to be charged and jailed.

• Read more:
• 'I can't breathe': 4 Minneapolis police officers were fired following their involvement in a black man's death after a cop knelt on his neck for 8 minutes
• A man was shot dead outside a Minneapolis pawn shop on the 2nd night of violent protests over George Floyd's death
• Minneapolis mayor calls for calm after a 2nd night of protests over George Floyd's death collapses into chaos, leaving a Target looted and an AutoZone on fire
• Eric Garner's mother says watching George Floyd plead 'I can't breathe' before dying in police custody was like having 'déjà vu all over again'
• Most Minnesota law enforcement agencies ban the neck-pinning maneuver used against George Floyd — but it's still allowed in Minneapolis
• George Floyd's relatives say he was 'everyone's favorite everything' as they call for police officers fired over his death to face murder charges
• Photos show thousands of protesters demanding justice in Minneapolis after police killed George Floyd
• New video appears to show police forcing George Floyd out of his car moments before an officer knelt on his neck for 8 minutes