Much of the police activity has been focused on New York’s Central Park, which appears to have been part of the gunman’s escape route.
The lake was trawled for a second day Sunday, and a discarded backpack found nearby contained a jacket and some bills from the board game Monopoly, but no gun, sources told CBS.
Police believe he rode into the park on his bicycle moments after the shooting and then caught a cab leaving the park on the Upper West Side.
Images released over the weekend show a masked suspect in the back of a taxi heading to the Port Authority Bus Terminal near Washington Heights.
He was not seen on any of the cameras leaving the station, so it is believed that he escaped on the bus.
In the same way, he arrived in the city 10 days before the shooting on a Greyhound bus coming from Atlanta.
He then checked into a dormitory, where he showed his face to the reception for a moment, which gave the police the clearest picture.