The new picture jolted some needed energy into the effort to find the 14-year-old, who is autistic and non-verbal.
Roughly 500 tips have poured in to find the boy, who was last seen on October 4 running out of his school in Long Island City.
A 13-year-old boy on the F train snapped the picture on Tuesday and later posted it on his Facebook page.
The photo shows a boy who resembles Oquendo wearing a beige jacket and green khaki pants, sitting and looking straight ahead. The teen who took the photo approached the other boy and asked if he was Avonte, but the boy didn't answer.
The NYPD confirmed the boy's identity Thursday. Still, Avonte's family remains hopeful he will be found alive.
"It's tough, it's just a tough situation right now," dad Daniel Oquendo said. "But we're hoping for the best."
The family spent Thursday following up on another possible sighting, this time on the Lower East Side. More specifically, they were focused on a garbage incinerator room where residents saw a person sleeping Tuesday night.
"He is alive, he's alive," resident Albert Nieves said. "I saw him."
Nieves said that at first, the person inside the incinerator room blocked anyone from coming inside, forcing the door shut.
The residents were terrified at first, but then Noemi Nieves said she glanced at the intruder's face and recognized similarities to Avonte.
"He looked a little bit, no expression, calm," she said."Very calm person, you know? He's walking very slow, slow."
The person slipped down the stairs and disappeared, but the building has easy access and plenty of hiding places.
"We couldn't see his weight, his frame," Albert Nieves. "But my mother says he has a thin frame. So he did fit the description."
The Nieves family wished they reacted quicker, but despite the disappointing news about the subway photo, they are upbeat.
"I hope he's here, and I pray to my God that he comes back to the same place," Noemi said. "Because my neighbor told me he was sleeping over there."
The reward for information leading to Avonte's safe return is up to $95,000.