At least four people were robbed on CTA trains in December and January in Lincoln Park and on the Near North Side.
In each incident, someone either snatched the victim’s property or used force to take it from them, Chicago police said.
The robberies happened at all hours of the day between Dec. 18 and Jan. 4, police said. Three of them happened on the Red Line, near the North/Clybourn, Grand and Chicago stations.
The other robbery happened on a Brown or Purple Line train near the Chicago station in the 700 block of North Franklin Street, police said.
Anyone with information about these incidents is asked to call Area Central detectives at 312-747-8380.