“Was he acting alone? Was he acting for other people? What was the motive? I simply, standing here in front of you, do not have all of the answers,” said Shea, chief of detectives. “These are all the questions we will pursue to make sure working with the prosecutors we have anyone responsible for this incident held to justice.”

Shea said police think Comello is the shooter but the investigation is far from over.

Comello was described as having limited previous contact with the NYPD, Shea said, but he would not be specific. Comello once exhibited strange behavior in a federal courthouse that prompted law enforcement to check him out, The New York Times reported without providing specifics.