NEW YORK— New York’s police commissioner says the school safety officer who was the last person to see an autistic boy before he disappeared 11 days go did nothing wrong.

Commissioner Raymond Kelly said Wednesday the officer encountered Avonte Oquendo,14, at the front door of the Riverside School in Queens and told him to go back upstairs. But he went down the hallway and out through a side door.

He hasn’t been seen since. His parents say they are suing the school.

Police have said Avonte was fascinated with trains. Officers searched all subway stations and tunnels and are working with authorities in New Jersey and Long Island in case Avonte got aboard a train leaving the city.

A $70,000 reward is being offered for information on the boy’s whereabouts.