This woman committed two daytime robberies late last week on the Green and Pink lines before getting away, police said.
The woman approached fellow riders on the train, snatched something from the victims' hands and ran off, police said.
Surveillance images shared by police show the suspect got off the train at the Ashland CTA station on the Near West Side.
Be on the lookout!
Police described the suspect as a black woman around 17 years old who's between 5-foot-4 and 5-foot-7.
Anyone with information on the robberies is asked to call police at 312-747-8382.
Photos above provided by Chicago Police Department.