Atlanta Mayor Andre Dickens sent a letter to city employees Friday afternoon in advance of the expected 4 p.m. video release of a brutal encounter between Memphis police and Tyre Nichols.

Dickens said he spoke with Memphis Mayor Jim Strickland this week, and said he and other city leaders are committed to “justice and healing in their community.”

“We know from experience that videos like this can rightfully spark emotional responses,” Dickens said in the letter. “I am a firm proponent of full participation, community dialogue and peaceful demonstration. Atlanta is the Cradle of the Civil Rights Movement, and the City is working to ensure that anyone who is looking to lift their voice in peaceful protest or demonstration in the days to come is able to do so safely.

“That also means we are remaining vigilant for those who might try to use the cover of protected First Amendment activities to conduct illegal acts of violence and destruction, which we will not tolerate.

Demonstrations over Atlanta’s police training facility turned violent last weekend, after a Georgia state trooper was shot in the abdomen and return fire killed a protester earlier in the week.

On Thursday, Gov. Brian Kemp signed an emergency order allowing him to deploy as many as 1,000 Georgia National Guard troops.

“Georgians respect peaceful protests, but do not tolerate acts of violence against persons or property,” Kemp wrote in the order, which expires Feb. 9.

Dickens said in the letter that city officials remain in close contact with state officials.

“While there are precautionary measures being put in place, we are not altering City operations or hours at this time,” Dickens letter says.