It was this Puerto Rican flag shirt, she later told police, that triggered a man to repeatedly harass her, getting up close and snarling "you should not be wearing that in the United States of America".
Irizarry then explained to the officer that the situation began when she requested that the group move since she had a permit.
"You are not going to change us". 'The world is not going to change the United States of America.
She responds that she's just at the park for a birthday party.
"You should not be wearing that in the United States of America", he said, pointing at her.
Ironically, the initial officer wound up taking the official report from Irizarry, who pointed out that she asked for his assistance multiple times.
Several minutes later, other police officers arrived to arrest Trybus. Like, this guy's just walking up to me. "She also says, "Officer, I feel entirely uncomfortable, can you remove ... please officer" as the officer casually walks away from her".
Now, an investigation has been opened into the incident, where the man-who was visibly drunk-verbally berated the woman and called her shirt un-American.
The man was placed under arrest and charged with assault and disorderly conduct.
The Forest Preserves wrote on Twitter on Monday that the investigation of the officer is "ongoing" and that he'd been assigned to desk duty "pending the outcome".
The park location was not identified in the Facebook post, but a Twitter army tracked the location as one of the areas supervised by the Forest Preserves Department of Cook County, which includes Chicago.
Another, longer version of the video, was posted to Facebook Live by the victim, Mia Irizarry.
A female officer asks to see his ID and can be heard telling him that he's intoxicated to which he replies "well that's your judgment".
"We have worked very hard since 2010 to make the Forest Preserves of Cook County a welcoming and safe place for all", she tweeted.
Rossello Tweeted: "I am sure @tonipreckwinkle will take matter into her hands as justice and diversity have been central to her exemplary career".
Preckwinkle called the video "completely unacceptable" and said she was "troubled" by the officer's response to the "terrible" incident.
"This is not the America we all believe in", he tweeted.
Puerto Rico was hit by a devastating storm, Hurricane Maria, last September. Although Puerto Ricans are USA citizens, they must register in one of the 50 states to vote in presidential elections.
The video even got the attention of Puerto Rico Governor Ricardo Rosello, who said he was "appalled, shocked, and disturbed by the officer's behavior". "I was denied entry into the Capitol complex by U.S. Capitol Police despite being a Congressman with identification, because my daughter was carrying a Puerto Rican flag and the officer doubted that I could possibly be a Member of Congress".