The teen, who can be seen in his selfies that police released Wednesday, walked up to a 48-year-old woman near East 129th Street and Madison Avenue about 12:30 a.m. and asked to borrow her phone, NYPD officials said.
She declined, so he asked her to dial some numbers for him, but then swiped her cell and fled east on 129th Street, officials said.
He then started taking photos of himself including one on the subway, police said.
He also took three shirtless photos of himself, police said.
Investigators were able to get the photos by accessing the victim's iCloud account, police said.
He's about 16 years old, 5 feet 10 inches and 145 pounds, officials said.
Anyone with information should contact Crime Stoppers at (800) 577-TIPS (8477).