WATCH: Aurora Police Use Pepper Spray at Elijah McClain Violin Vigil

Aurora, Colorado, police on Saturday forcefully swooped in on a peaceful violin vigil for Black 23-year-old Elijah McClain, who died after being put in a chokehold by police and injected with ketamine by paramedics last year.

McClain’s death is being investigated by the state attorney general, after enormous public outcry, including a Change.org petition with nearly 4 million signatures.

Decked out in riot gear, officers fired foam rounds at protesters, hit them with pepper spray and, in one case, rolled a canister of some sort of gas into the crowd.

The police department came under fire for the show of force, with Twitter coming down firmly on the side of the vigil-goers, and some even calling police’s actions “ghastly.”

Here’s what you need to know:

The Vigil Was Intended As a Peaceful Tribute To McClain, Who Played the Violin, & Drew World-Famous Violinists

Famed violinists from across the country flew in to be a part of the vigil, local NBC 9 reported.

“I see myself in him a lot. That easily could have been me in a lot of situations,” six-time Grammy nomiee Ashanti Floyd told the outlet. “I’ve heard about it for a long time but I just watched the video a couple of days ago. It really made me think about life and how blessed I am.”

Boulder, Colorado, cellist Joy Adams told Violist.com that the event was a “peaceful protest, with people carrying violins and cellos, playing in honor of Elijah McClain.”

“There were children in the crowd, musicians playing, people holding candles and roses and sitting on the ground.”

The vigil was preceded by a protest by the Party for Socialism and Liberation, then a youth march thousands-strong, the Sentinel Colorado reported

Police in Riot Gear Descended Around 8:30, Using Pepper Spray & Foam Rounds to Disperse the Crowd; Violinists Continued Amid the Chaos

Around 8:30 p.m., the violin vigil kicked off, with a crowd of people largely sitting peacefully. Meanwhile, a nearby group of protesters were in a standoff with police outfitted in riot gear nearby, local journalist Marc Sallinger tweeted from the scene.

Police said via Twitter that some protesters had “armed themselves with rocks and sticks” and declared the protest an unlawful assembly. “Pepper spray may be used,” they warned in a subsequent Tweet.

Police soon advanced on the vigil with batons and pepper spray, numerous videos showed. Sallinger said pepper spray was used on a number of people in the park where the vigil was held, including a camera crew.

During the confrontation, at least one violinist continued playing, making for a surreal scene, Sallinger also reported.

In another video, police in riot gear can be seen advancing on a small group and using pepper spray directly on a person’s face as they appear to scuffle with one of the advancing officers. The person falls to the ground, covering their head, then when they gets up, police spray them again.

A number of people at the event alleged police lobbed tear gas into the crowd. Aurora police denied they used tear gas in a Tweet and disabled replies.

Several people quote-tweeted the police response, however, and included video showing officers lobbing a canister of some kind of gas into the crowd.

Detective Faith Goodrich, a spokeswoman for the Aurora Police Department, told Heavy on Monday that officers used smoke canisters.

“It contains smoke and no irritants,” she said. “It is used to help encourage the protesters to move away and towards a safe area.”

The Vigil Eventually Moved to a Nearby Parking Lot, Where the Violin Music Made for a Haunting Contrast to the Day’s Violence

Police eventually allowed the violin vigil to continue in an adjacent parking lot, with about 1,000 people remaining, the Sentinel reported. Denver photographer Giles Clasen said on Facebook that Floyd and violinist Lee England Jr. then played while a police helicopter hovered overhead.

Floyd posted a video from the vigil to Facebook, writing, “Aurora, great job. We heard you, and promise to not take our foots off the gas. I am Elijah McClain. We are all Elijah McClain. I’m leaving back to Atlanta tonight, but I just wanted to say, thank you for taking a stand for people who look like me.”

“One of the most surreal scenes I’ve ever seen,” Sallinger tweeted. “Music is powerful.”

Aurora Police Were Roundly Criticized After the Video Spread, With the Show of Force Called A ‘National Disgrace’

Editor of the Sentinel, Dave Perry, wrote an op-ed Sunday insisting that police did use tear gas. He called it a “cruel and ghastly mistake.”

According to Perry, even if the canisters thrown at protesters contained pepper spray, it is, functionally and legally, tear gas.

“Aurora Police failed the community yesterday when they used chemical warfare against protesters who were behaving criminally — and potentially hundreds more who were not,” he wrote.

Healthcare advocate Kendall Brown tweeted, “Shame on you @AuroraPD” and shared Perry’s distaste for police’s distinction between pepper spray and tear gas.

Twitter user Respectable Lawyer re-tweeted some of the most widely shared videos of the event and said they showed “just pure Good versus Evil s**t.”

Another user called the incident a “national disgrace” and evidence that our systems are “terrifyingly broken.”

The Aurora Police Department told Heavy Monday that officers did not use tear gas on protesters and declined further comment on the incident.

READ NEXT: Jeremy Christian: White Supremacist Train Killer Gets Life In Prison