The suspect has hit subway stations across Manhattan.
Authorities have studied the times of the robberies, and they believe the suspect is a teenager himself who is targeting his victims before and after he goes to school.
Police say the suspect either follows his victims onto the platform or onto the street, then starts a conversation with them so they let their guard down. Then, he displays a gun or knife and robs them of iPods and cell phones.
"It makes you uneasy, knowing something like that is happening," Bronx resident Victor Rosado said. "But it's not like it's the first time. So you know things like that happen, so it kind of just puts you on high alert.
There have been seven incidents in the last six weeks, and police say it's not just happening in the East Village. There have also been robberies in Lower Manhattan and on the Upper West Side. All of the victims are teenagers.
The suspect is described as a black male, approximately 18 to 22 years old, standing 5-foot-3 to 5-foot-5 and weighing 130 to 150 pounds.
Anyone with information is asked to call Crime Stoppers at (800) 577-TIPS (8477). The public can also submit their tips by logging onto Crime Stoppers' website at NYPDCrimeStoppers.com or by texting their tips to CRIMES (274637), then enter TIP577.