Police said the 67-year-old grandmother was riding the train around 12 p.m. Thursday. She was reading on her Kindle when a man approached and, completely unprovoked, punched her in the face.
The victim's son told ABC7 Eyewitness News that his mother underwent eye surgery, but is now blind in her left eye. She had never met the suspect.
The suspect got off at one stop, while the victim got off at another stop to call for help.
Even the most vigilant CTA riders were stunned by the attack.
"Quite frankly, it's appalling," said rider Jack Schultz. "Why would someone take the time out of their day to hit somebody's grandmother?"
Chicago police tweeted that a man had been taken into custody Friday afternoon after surveillance images were released to the public. They thanked members of the community and officers, who CPD Spokesman Anthony Guglielmi said recognized a possible offender from the photos and were able to locate him.
Thank you to you the public and everyone for your assistance in finding this suspect. The partnership between the Police and community works and this is just the most recent example. Thank you! pic.twitter.com/YnLOcyPiap— Chicago Police (@Chicago_Police) June 15, 2018
Special thanks to 14th District Officers @ChicagoCAPS14 who recognized a possible offender from surveillance photos. @cta has a sophisticated, hi-def camera system in the entire transit network. If you commit crimes on @cta #ChicagoPolice are watching and you wont get very far. https://t.co/v8dzsKMaoK— Anthony Guglielmi (@AJGuglielmi) June 15, 2018
The suspect remains in police custody and charges are pending.