Police issued a warning to residents of recent robberies in the Albany Park neighborhood on the Northwest Side.
The two robberies happened after sundown within a block of each other on Ainslie Street, Chicago police said in a community alert.
In one, the robberimplied they had a weapon, police said. In the other, they struck the victim.
The robberies happened about 7:20 p.m. in the 3000 block of West Ainslie Street and about 10:20 p.m. in the 3100 block of West Ainslie, police said.
The suspect is between 18 and 25 years old, standing 5-foot-10 and weighing 140 pounds, police said.
Anyone with information was asked to call detectives at (312) 744-8263.