Boston Police Headquarters Quiet and Focused

Instead of a food truck outside the Whittier Health Clinic, across from Boston Police's Headquarters, there were armed guards and a North Eastern Massachusetts Law Enforcement Council Incident Command Center, on Tuesday.

Normally busy, Tremont Street had fewer vehicles than normal, with federal, state and local personnel hurrying back and forth from the control center and into Boston Police Department's Headquarters.

Inside headquarters visitors were having to show identification, with their names and addresses being written down by an officer at the building's entrance before going through a metal detector. Before Monday's Boston Marathon's events, visitors to Boston Police's Headquarters did not need to show identification, and were often allowed to enter without going through the metal detector. The officer manning the entrance said the new regulations will remain until further notice.

First floor staff, who normally deal with taxi drivers applications or requests for police reports - were fielding and redirecting random tips from all over the country, said one staff member.

The first floor of headquarters had few visitors, with an apparent increased Boston Police presence. Often a jovial place with laughter and conversation, most people seemed to be speaking with quiet voices.