A police officer from the NYPD Counterterrorism unit search a commercial van at a security checkpoint on 34th Street, Friday Jan. 31, 2014 in New York. Despite no specific terror threats against the Super Bowl, federal and local authorities have heightened security. (AP Photo/Bebeto Matthews)

Police search a commercial van at a security checkpoint on 34th Street, Friday Jan. 31, 2014 in New York. (AP Photo/Bebeto Matthews)

New York City Police K9 officer Kirk Boone and his police dog Kato keep their eyes and ears on crowds attending Super Bowl attractions on Broadway, Friday, Jan. 31, 2014, in New York. Security was tight in the area as the day nears when the Seattle Seahawks will play the Broncos Sunday in the NFL Super Bowl XLVIII football game in East Rutherford, N.J. (AP Photo/Ted S. Warren)

Members of U.S. Homeland Security unit, left, patrol a train platform with a K-9 team from Amtrak Police at Penn Station on Thursday, Jan. 30, 2014, in New York. (AP Photo)

Members of U.S. Homeland Security monitor a section of Penn Station on Thursday, Jan. 30, 2014, in New York. Federal and local authorities have studied intelligence about recent attacks on mass transit in Russia and heightened security for the Super Bowl, despite no specific terror threats. (AP Photo)

Amtrak Police K-9 team patrol as passengers prepare to embark a train at Penn Station on Thursday Jan. 30, 2014 in New York. Local law enforcement are getting additional help from U.S. Homeland Security's Visible Intermodal Prevention and Response (VIPR) security unit for the Super Bowl. (AP Photo)

A temporary surveillance camera is installed on a Times Square light post, Thursday Jan. 23, 2014 in New York. New York City police are blanketing midtown Manhattan with temporary surveillance cameras as one of many security measures being taken to protect visitors for the Super Bowl. (AP Photo/Bebeto Matthews)

A technician works on a light post where a temporary surveillance camera is installed, Thursday, Jan. 23, 2014 in New York as one of many security measures being taken to protect visitors for the Super Bowl. (AP Photo/Bebeto Matthews).