As ABC7 first reported last month, Officer Fiorito is being investigated by the cook county state's attorney's office.
The lawsuit also claims Officer Fiorito then perjures himself in court testimony after making the arrests.
ABC7 has learned that the federal civil case against him is about to double in size with 21 new plaintiffs joining it. And even though her office is conducting a grand jury investigation against him, Cook County State's Attorney Anita Alvarez continues to use him as a witness in court.
ABC7 has obtained more exclusive dash cam video taken from inside Fiorito's squad car. He was ordered to use the surveillance equipment back in March because of all the complaints against him. WATCH VIDEO
In one video, Fiorito is following Christopher Quinn who's driving on the North Side back in June. Officer Fiorito wrote in his police report that Quinn was "driving recklessly." Fiorito arrested him for driving under the influence. But last week, Quinn's DUI charge was dismissed, largely because of the video which lawyers say proves Fiorito is committing perjury.
"I've never seen a video that's so starkly different than what the police officer wrote down on the report," said April Preyar, criminal defense attorney.
Preyar specializes in DUI cases. She says the video evidence and the incident ABC7 showed viewers last month have damaged Fiorito's credibility beyond repair.
In one scene, Fiorito arrested Michael Vaughn for DUI, claiming he failed field sobriety tests. But last week a judge lifted the suspension of his driver's license.
It's a story told over and over again by drivers in the Boystown neighborhood, where Fiorito is based and wrote hundreds of DUI tickets. Many claim he followed them after leaving gay bars. And many have joined in a federal civil lawsuit against Fiorito.
Jackie Rosignal is one of the 21 new plaintiffs. She signed on after seeing ABC7's last report. "I think he deserves to go to jail. He is a cop and he's supposed to be trusted and he's perjuring himself in court against people who are innocent," said Rosignal.
Yet, prosecutors continue to use him as a witness in court for his DUI cases that are still pending - not up on the witness stand anymore but they're going on paper, meaning they're still using his police reports as evidence.
Cook County State's Attorney Anita Alvarez ordered a grand jury investigation into Fiorito back in March. But there's been no indictment.
Gay activist Andy Thayer says Alvarez is doing it the Chicago way -- protecting a crooked cop.
"People are going to court, facing these charges, losing work, some are losing jobs as a result of this officer and as a result of Anita Alvarez' lack of action and we're very upset about it, we're angry about it," said Andy Thayer, Gay Liberation Network.
ABC7 asked for an interview with state's attorney Anita Alvarez on Wednesday, but we were told she was not available.
A spokesperson says Officer Fiorito has not been used on the witness stand ever since he was placed on desk duty on October 7 and has been used 'on paper' once since then.
Spokesperson Sally Daly of Cook County District Attorney's Office says there are serious questions about Fiorito's credibility. Daly told ABC7 he won't be used for any DUI cases in the future, not even on paper.
ABC7 tried to get a response from Officer Fiorito or his attorney as well, but they did not return our calls.