Three people were arrested after a wild brawl Monday evening with a K9 security team on a CTA Red Line platform on the South Side.

Video of the fight at the 69th Street stop surfaced on the same day the transit agency and police showed off a new high-tech solution to keep passengers safer.

On Thursday, CTA and Chicago Police Department leaders showed off a new Strategic Decision Support Center for the CPD public transportation section, where officers are able to keep track of crime in real time.

The technology helped in a fight involving a K-9 security crew at the 69th Street stop on the Red Line.

That fight was captured on cell phone video and shared all over social media. The suspects were also caught on video by CTA's network of security cameras, which led to the arrests.

Cell phone video shows a situation off the rails, and a private CTA security guard climbing off the tracks amid a brawl on the platform.

Police said the fight – shared on social media – took place shortly after 8 p.m. Monday at the 69th Street station.

Video of the fight shows someone taking swings at a K-9 handler, and hurling a trash can at his dog. The chaos continued; full of punches, shoves, and the dog appears to make contact with a person's hand. The dog is seen biting at and lunging towards people.

The video also shows one of the security guards instructing the dog to bite. 

According to police, no dog bites were documented.

"That type of behavior will not be tolerated under any circumstances," Chicago Police Supt. Larry Snelling said.

The superintendent said three people were arrested for that brawl, thanks in part to the Strategic Decision Support Center at the 1st District station, specifically dedicated to the department's mass transit unit.

The facility functions as a nerve center of sorts, allowing embedded detectives to monitor thousands of cameras to track crime in real time across the CTA.

CPD has similar rooms at all 22 police districts across the city to monitor crime across the city – not just on the CTA.

Police said detectives in the transit unit's Strategic Decision Support Center on Wednesday spotted one of the suspects from Monday's brawl at another station. Officers followed his movements from a train to a bus, where they arrested him for his role in Monday's brawl.

"To have detectives and police officers in here throughout the day monitoring CTA is a huge step to protecting our riders and employees," acting CTA President Nora Leerhsen said.

Leerhsen said the mass transit unit's Strategic Decision Support Center shows CTA's commitment to safety; a commitment challenged by incidents like Monday's brawl at the 69th Street station.

"I'm on CTA every day, multiple times a day. I feel comfortable riding CTA. I love CTA. I feel strongly about that every rider should feel safe riding CTA, and it's been a focus of mine since taking over as leader of CTA," Leerhsen said.

Police said 23-year-old Dievion Richardson has been charged with two counts of aggravated battery after the fight with security guards. He also faces drug possession charges and a citation for smoking on the CTA. Charges are pending against two other people.