A former coworker of the Mercy Hospital gunman is suing the Chicago Housing Authority, saying it ignored her when she complained about his sexual harassment because it wanted to retaliate against her for complaining about other CHA personnel.

Rhonda Barrett filed her lawsuit Thursday in Cook County Circuit Court, alleging that the CHA brushed aside her complaints about Juan Lopez’s conduct, which included “swearing at her in front of employees and the public, bullying her physically, touching her shoulders and pushing on her body, using his legs to reach out and touch the Plaintiff.”

Lopez, 32, killed a Chicago Police officer, a doctor and a pharmacy resident during a shooting spree on Nov. 19 inside Mercy Hospital in Bronzeville. He died in a shootout with police.

Before the bloodshed, Barrett had unsuccessfully tried to report Lopez to the CHA, according to the suit. She had worked there since September 2015.

That’s when Barrett alleges the harassment — and subsequent retaliation campaign — began.

“Lopez bragged to Plaintiff that he would not face employment consequences for his conduct because of powerful political alliances at CHA and within the City of Chicago,” the suit said.

During a June complaint, Lopez in turn accused Barrett of sexually harassing him, according to the suit. She was terminated this September “on his word alone.”

Since the slayings, several allegations about Lopez’s threatening behavior toward women have surfaced.

The list includes claims that he promised to “cause a scene” at his ex-wife’s workplace, that he made his former colleagues at the Chicago Fire Department academy “incredibly uncomfortable” and that he showed up at Mercy Hospital because he “couldn’t let it go” after his ex-fiance Tamara O’Neal ended their engagement.

Barrett alleges the CHA was negligent in hiring Lopez despite the complaints against him at the Chicago Fire Department, and negligent in not firing him despite Barrett’s repeated complaints.

She also claims the agency allowed Lopez’s conduct to continue to retaliate against her for past complaints she had made against other CHA personnel. That included reporting her former supervisor for showing up at her home, inviting her to “fake” training sessions and exposing his genitals and sticking them in front of her face, according to the suit.

As a result, Barrett’s new boss punished her with poor work performance reviews, the suit said.

CHA spokeswoman Molly Sullivan declined to comment Friday, stating, “CHA has not been served with the lawsuit and therefore cannot comment on it.”

After the shooting, CHA had issued a statement, saying it hired Lopez in February, and he worked there as an associate program specialist at its customer care center in the Loop. He underwent typical background checks before he was hired, the CHA said, and no complaints about him turned up.