UPDATE:
They still don't have video of the attack. All they've got are people on video who were in the area.
https://www.chicagotribune.com/news/...ml#nt=screamer
“They are outside on a street walking. They are in the area that we have determined it could have taken place… in the time and the area,’’ Guglielim said. “It certainly leads us to have questions for them.’’