A federal judge has ruled in favor of a group of protesters who sued the St. Louis police forces.

The judge ordered the police to warn protesters before using chemical agents like tear gas and allow them enough time to disperse before using the weapons.

Following a grand jury's decision to not indict former police officer Darren Wilson for the death of Michael Brown, protests erupted throughout the country. In Ferguson, Missouri, where the incident happened, protesters took to the streets, blocking highways and engaging police. A smaller group also looted and vandalized parts of the city. In response, police fired tear gas, flash bangs and pepper spray to disperse the crowds of both looters and protesters.

A group of protesters took the police to court, arguing their constitutional rights were violated, according to The Associated Press.

On Thursday, U.S. District Judge Carol Jackson ruled in favor of the protesters, granting them a temporarily restraining order against the police. The case had been brought against Missouri State Highway Patrol Capt. Ron Johnson, St. Louis County Police Chief Jon Belmar and St. Louis Police Chief Sam Dotson, who led the "unified command" formed in August to handle the protests.

In her ruling, Judge Jackson wrote that the evidence "establishes that law enforcement officials failed to give the plaintiffs and other protesters any warning that chemical agents would be deployed and, hence, no opportunity to avoid injury."

As part of her decision, Judge Jackson ordered the police to warn protesters before using chemical agents against them and give them a "reasonable" time for people to leave. However, she did not provide a specific time frame, leaving that to police, the St. Louis Post-Dispatch reports.

She also rejected the police's request to use tear gas "as a last resort."

The protester's attorney Thomas Harvey praised the decision, according to the AP.

"We were simply asking the judge to require police to make it possible for law-abiding citizens to comply with their order to disperse and give them time to exit the area prior to tear gas being deployed," Harvey said Friday. "They need to separate criminals from protesters and she made the distinction very clear."

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