Controversy surrounds photo of Chicago cop kneeling outside police union office

A Chicago police officer is appearing to send a very pointed message on social media to the police union.

The officer has posted a picture of herself kneeling in front of the union's office -- while in uniform and holding a Black Lives Matter sign -- after the Fraternal Order of Police president appeared to threaten officers who take part in protests.

"If you kneel, you will be brought up on charges and thrown out of the lodge,” FOP President John Catanzara said last week.

Catanzara says he knows why the photo was taken.

"I think it's almost a dare,” he said. "It’s a challenge for us to do something about it.”

The officer who took the photo has been on the job since the 90s. She posted the public photo to her Facebook page, as well as a message against police brutality and racism.

FOX 32’s Tia Ewing asked Catanzara if he believes black lives matter.

“I believe all lives matter,” he responded.

CPD sent FOX 32 their code of conduct. There is a rule on page 9 that says, “Failure to wear the uniform as prescribed” is a violation.

The president of Metropolitan Alliance of Black Law Enforcement says the officer in the photo will face backlash.

"What we are seeing is what blacks in law enforcement hear all the time. How come black officers won't step up? We are seeing why. Not only is the agency she works for saying she will have blowback. Now the very union she pays for is saying we will expel you and charge you,” said Henry Hemphill.