A Red Line beating that might have remained just another unsolved transit assault was cracked open when Chicago police detectives came upon Facebook video of the attack and recognized two of the assailants, prosecutors said.
Cops arrested Mary Webb, 22, and Alaiyah King, 20, after they recently appeared in court for another case in which they are charged with assaulting a CTA passenger in January.
According to prosecutors, the latest victim was riding the Red Line on the South Side on February 16 when she noticed a group of people fighting on the other end of the railcar. Some members of the group thought she was recording the altercation on her phone, so Webb and King confronted her, prosecutors said…