A 13-year-old snapped the picture Tuesday and later posted it on his Facebook page.
Authorities said Thursday that the boy shown in the photo went with his mother to see police.
The boy resembles 14-year-old Avonte Oquendo, who was last seen on Oct. 4 walking out of his Queens school.
The teen who took the photo approached the boy and asked if he was Avonte. But the boy didn't respond.
Avonte's parents had said they couldn't be sure that the photo showed their son.