NEW YORK — New York City police have determined that a photo of a boy riding a subway train is not that of an autistic boy missing for nearly a month.

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 (ah-VAHN'-tay oh-KEHN'-doh), 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.