People have been talking about pepper spray on social media.

It was used by police during protests downtown Friday following former St. Louis police officer Jason Stockley's not guilty ruling. There's been some debate and some confusion, even among legal experts, about how police can use pepper spray.

So, 5 On Your Side set out to verify those rules.

The rules about pepper spray have changed a lot since the events in Ferguson in 2014. That's because protesters sued the "unified command." That group includes both St. Louis city and County Police, plus the Missouri Highway Patrol.

They said using chemical agents to break up crowds violates first amendment rights.

Protesters filed a lawsuit, which we were able to find. That lawsuit clearly lays out the new rules for using chemical agents including pepper spray. First, officers must issue clear and unambiguous warnings. They also need to give people time to leave the area.

But the St. Louis city Interim Police Chief Lawrence O'Toole says there's an exception.

"We're fully aware of that order and we're following that order. But, again, that order also contains language that said if there's not time for that because we're under attack we can utilize chemical munitions," said O'Toole.

The lawsuit settlement says none of those new rules apply to situations that turn violent and when bodily harm or damage to property is imminent.