NEW YORK — The National Football League’s internal security apparatus would be the envy of many American police departments. Run by a former commissioner of the Pennsylvania State Police, its staff includes former agents from the upper echelons of the FBI. The league employs a network of private security contractors. The NFL reported spending $2.3 million on “investigator fees” in its last annual filing with the IRS. Yet for all that muscle, the league has insisted for weeks that it was …