ST. LOUIS (Reuters) – A third day of protests began peacefully in St. Louis on Sunday, after violent clashes erupted between police and demonstrators the previous two nights over the acquittal of a white former police officer in the 2011 fatal shooting of a black man.

Hundreds of protesters assembled before the barricaded police headquarters, and the growing crowd then marched past a line of riot police near St. Louis University without incident.

Events started peacefully the previous two nights, but violence broke out after sundown on Friday and Saturday, shattering storefront windows and evoking memories of the riots following the 2014 shooting of a black teenager by a white officer in nearby Ferguson, Missouri.

The latest protests began after Circuit Judge Timothy Wilson on Friday acquitted former St. Louis police officer Jason Stockley, 36, of first-degree murder in the 2011 shooting death of Anthony Lamar Smith, 24.

Sunday’s crowd appeared to be the largest of the three days at more than 1,000 people.

An informal group known as the Ferguson frontline has organized the protests, focusing on what it describes as institutional racism that has allowed police to be cleared of criminal wrongdoing in several shootings of unarmed black men.

“Windows can be replaced. Lives can‘t,” said Missy Gunn, a member of Ferguson frontline and mother of three children including a college-age son. She said she feared for him every night.

As activists marched through central St. Louis, drummers set the beat for the chant: “If we don’t get no justice, y‘all don’t get no peace.”

Demonstrators also called out: “Anthony Lamar Smith” and later lay down in front of police headquarters, simulating death in a “die-in.”

On Friday, 33 people were arrested and 10 officers injured, police said.

Violence flared anew on Saturday night when about 100 protesters, some holding bats or hammers, skirmished with police who were in riot gear, resulting in at least nine arrests.

More serious clashes broke out in 2014 in Ferguson, a suburb of St. Louis, following the killing of 18-year-old Michael Brown by a white police officer who was not indicted.

The Ferguson protests gave rise to Black Lives Matter, a movement that has staged protests across the United States.

Smith was shot in his car after Stockley and his partner chased him following what authorities said was a drug deal. Prosecutors argued that Stockley planted a weapon in Smith’s car, but the judge believed the gun belonged to Smith.