Police and federal officials in the Twin Cities are taking precautions ahead of Friday night's anticipated release of police video from Memphis showing officers fatally beating a young man three weeks ago.

The five officers involved in the beating of Tyre Nichols, a Black man, were charged with murder Thursday in the country's latest instance of police brutality targeting mostly people of color. All of the officers, who have since been fired, are Black.

Nichols died three days after a confrontation with the officers during a traffic stop Jan. 7. Nichols' mother, RowVaughn Wells warned supporters of her family about the "horrific" nature of the police video but pleaded for peaceful protests.

Ashlee Sherrill, a spokeswoman for the federal Bureau of Alcohol, Tobacco and Firearms in St. Paul, said the field division sent an alert to metro-area firearms retailers Friday morning in light of the rioting that erupted in the Twin Cities after a bystander's video of George Floyd's death in May 2020 under the knee of a Minneapolis police officer was viewed by millions around the world.

"Given the experience we've had and what's going on in Memphis, out of abundance of caution we wanted to make sure our licensees could protect firearms and their acquisition and disposition records," Sherrill said.

Pawnshops and other retail outlets were among the many buildings that were damaged in the wake of Floyd's death, but there were no reports of gun shops or other licensed firearms sellers in the Twin Cities specifically targeted by looters.

"We're keeping a very active eye on things," said John Monson, owner of Bill's Gun Shop & Range in Robbinsdale. "We have the means to secure the firearms. After the last riots, we added a whole lot of security measures, and we haven't undone those."

As a way to speed police response, he said, the gun shop's burglar alarms automatically contact 911 in the event of an attempted break-in.

The store, which is a mile west of the Robbinsdale border with Minneapolis, was boarded up for three weeks during the unrest after Floyd's death. Monson said it "has secure storage spots that are impenetrable to move things."

The Minnesota National Guard was monitoring developments related to potential protests but had not activated any troops as of Friday afternoon. Minnesota Public Safety Commissioner Bob Jacobson said in a statement that state resources were available if needed and that the state stood ready to help local and federal agencies if asked.

In Minneapolis, Police Chief Brian O'Hara ordered that concrete barricades and metal fencing be erected as a precautionary measure outside headquarters in two police precincts. Officers' regularly scheduled days off were canceled to bolster staffing through the weekend.

In an internal video message to police rank and file Monday, O'Hara braced personnel for the Memphis video and outlined clear expectations should large-scale protests erupt in Minneapolis.

He said officers have a duty to ensure that citizens can peacefully assemble and exercise their constitutional rights, noting that police are strictly prohibited from "arresting, detaining or threatening to arrest or detain anyone on the basis of any activity that is protected by the First Amendment."

In the video obtained by the Star Tribune, O'Hara said that "should you be called upon to carry out the difficult task of serving in the face of unrest, I expect that you will serve with honor and that you will treat all people with dignity and respect.

"Force shall not be used unless it is absolutely necessary — and is in response to a threat to a person's safety. I expect any force used to be proportional to the threat received. That means when the threat is over, the force is over."

The chief's instructions come amid a federal court injunction barring Minneapolis police from using rubber bullets, Mace and tear gas as crowd control measure against demonstrators.

The U.S. District Court imposed those sanctions after a class-action lawsuit by the ACLU alleging that Minneapolis police used unnecessary and excessive force to suppress protected speech in the immediate aftermath of Floyd's murder. Twelve protesters, including several who were injured by police projectiles, won $50,000 each in a settlement with the city last fall.

The Minneapolis Fire Department was also beefing up staffing through Sunday with the St. Paul Fire Deparment and State Fire Marshal on standby to provide aid, according to a planning document obtained by the Star Tribune.

In St. Paul, police Sgt. Mike Ernster said officials there were preparing for possible unrest much like in other cities. He declined to give specifics other than to say that the Police Department "will have more officers out this weekend if any unrest occurs."

"We have been in communication with our local, state and national law enforcement partners in an effort to ensure those lines of communication are there, and we will work together if needed," Ernster said.

In a statement posted on social media, St. Paul Police Chief Axel Henry expressed condolences to Nichols' family and his own "deep sorrow" in advance of the video's release.

"As a community, we must come together to decry these acts and create a better future," Henry wrote.

Bloomington Police Chief Booker Hodges, who was assistant state public safety commissioner during the 2020 unrest in the Twin Cities, said his department had "robust plans in place should something arise."

However, he said he did not expect anything to happen.

"This place as a state is still healing people are still rebuilding," Hodges said. "For people that want to come and mess up that rebuilding, I don't think our community here is going to tolerate that. I don't think that's where our community is at right now."

Staff writers Kyeland Jackson and Reid Forgrave and the Associated Press contributed to this report.