It's on the Chicago Tribune here about 3/4 down the page:
http://www.chicagotribune.com/news/local/breaking/ct-trump-protest-scene-20160311-story.html
Here is a different shot of the incident:
http://www.blazingcatfur.ca/2016/03/11/a-vibrant-and-diverse-crowd-communists-and-assorted-student-radicals-riot-in-order-to-thwart-trump-speech-in-chicago/
http://www.blazingcatfur.ca/wp-content/uploads/2016/03/Riot-e1457745935890.jpg
