Demonstrators are gathering in Cleveland Saturday to protest the acquittal of a white police officer who was charged in the shooting deaths of two unarmed black suspects. Officials have urged calm in the aftermath of the controversial decision, which has received national attention and been widely criticized as unjust on social-media sites.

Crowds of peaceful demonstrators turned out Saturday morning in front of Cleveland’s Justice Center Complex upon hearing that the verdict was set to be read in the case of officer Michael Brelo, who was charged with two counts of voluntary manslaughter in the killing of Timothy Russell and Malissa Williams. Cuyahoga County Common Pleas Judge John P. O’Donnell announced he found Brelo not guilty on both charges, as well as on a lesser charge of felonious assault.

Wary of civil unrest similar to that which unfolded after police-involved killings in Baltimore and Ferguson, Missouri, officials have called on protesters to remain peaceful. “I firmly believe that the First Amendment gives every citizen a rightful path to speak out and protest against that which they do not like,” Cuyahoga County Executive Armond Budish said in a statement. “However, the path to free speech ends at the door to violence.”

Authorities put the National Guard on standby ahead of the reading of the verdict in anticipation of possible violence.

Brelo, 31, was the only officer charged in the Nov. 29, 2012, shooting and killing of Russell, 43, and Williams, 30. Thirteen police officers were involved in the incident, which was sparked by a high-speed chase after Russell ignored a plainclothes officer’s instructions to pull over after a turn-signal violation. More than 100 rounds were shot at the 1979 Chevrolet Malibu by police officers, but prosecutors argued that Brelo’s decision to fire from the hood of the car after the chase had already ended made him criminally responsible.

The verdict has been characterized as a major setback for justice by U.S. Rep. Marcia L. Fudge of Ohio. “The verdict is another chilling reminder of the broken relationship between the Cleveland Police Department and the community it serves, Fudge, whose congressional district encompasses parts of Cleveland and Akron, said in a statement Saturday.

This sentiment was echoed on social-media sites: