The Arlington County Police Department (ACPD) begins securing the perimeter of the Pentagon Reservation just minutes after the Pentagon attack occurred. [Washington Post, 9/20/2001; Goldberg et al., 2007, pp. 162; Defense Media Network, 9/11/2015] Corporal Barry Foust and Officer Richard Cox of the ACPD witnessed the attack on the Pentagon, at 9:37 a.m. (see 9:37 a.m. September 11, 2001), and immediately called the Arlington County Emergency Communications Center to report what they had seen (see (9:36 a.m.-9:39 a.m.) September 11, 2001). ACPD headquarters then sent a pager message to all members of the department with instructions to report for duty, thereby initiating an immediate response to the incident.
Arlington Police Take Charge of Security – Lieutenant Robert Medairos was the first ACPD command-level official to reach the scene and took command of the department’s response there. [US Department of Health and Human Services, 7/2002, pp. C6-C7 
] While the Defense Protective Service (DPS)—the law enforcement agency that guards the Pentagon—has exclusive jurisdiction within the Pentagon Reservation, the ACPD has jurisdiction around it. [US Department of Health and Human Services, 7/2002, pp. C1 ; Historical Office, Office of the Secretary of Defense, 1/31/2006 ; Defense Media Network, 9/11/2019] Medairos therefore promptly comes to an arrangement with the DPS for the ACPD to secure the perimeter of the Reservation.
Police Close All Roads around the Pentagon – Along with his colleagues Lieutenant Brian Berke and Sergeant James Daly, he assesses the road network conditions and identifies 27 intersections that require immediate police posting. [US Department of Health and Human Services, 7/2002, pp. C7 ; Goldberg et al., 2007, pp. 162] At 9:42 a.m., he orders the closure of all roads surrounding the Pentagon. [Washington Post, 9/20/2001] Berke and Daly take action to keep all traffic except emergency vehicles off the feeder roads to Route 27, just west of the crash site. Police officers close Route 27 to regular traffic and prevent first responders from blocking emergency lanes or parking their vehicles haphazardly. The Pentagon’s parking lot and the field adjacent to it are cordoned off, and guards are posted around the perimeter. [US Department of Health and Human Services, 7/2002, pp. C7 ; Goldberg et al., 2007, pp. 162] Sniper teams are set up to monitor the local highways. ACPD officers monitor traffic around the area and screen pedestrians entering the crash site. Anyone delivering equipment has to be escorted to the Pentagon by police officers. [Middletown Press, 1/29/2002]
Other Police Departments Will Assist the Response – The ACPD has a memorandum of understanding with all the other police departments in the area and it calls these departments to request assistance. [Historical Office, Office of the Secretary of Defense, 1/31/2006 ] Consequently, by 11:00 a.m., over 100 law enforcement officers will have reported to the staging area at the Pentagon. Along with members of the ACPD, officers will have come from Fairfax County Police Department, Alexandria Police Department, Arlington County Sheriff’s Office, Arlington County Park Rangers, and the Immigration and Naturalization Service. Captain Rebecca Hackney will soon take over from Medairos as the commander of the ACPD at the Pentagon. Deputy Chief Stephen Holl, who was at a meeting in Richmond, Virginia, when the Pentagon attack occurred, immediately heads back to Arlington after hearing what happened, and will arrive at the ACPD command post at the Pentagon around midday and take over command of the ACPD from Hackney. [US Department of Health and Human Services, 7/2002, pp. C6-C7, C13 ; Goldberg et al., 2007, pp. 162, 164]
12:00 p.m. September 11, 2001 and After: FBI Searches Pentagon Surroundings for Plane Debris
Beginning shortly before midday on September 11, 2001, and continuing until September 12, the FBI conducts a careful search across the grounds of the Pentagon, looking for remnants of the aircraft that hit the building. [PBS, 9/12/2001; Washington Post, 9/12/2001; Goldberg et al., 2007, pp. 159] FBI Special Agent Tom O’Connor is in charge of the initial evidence recovery operation at the Pentagon. His first priority is to locate and gather all the airplane parts and other pieces of evidence from the lawn on the west side of the building. He sends out all available agents to conduct a grid search. The lawn is divided into quadrants, and then agents walk back and forth, sticking a small flag near any evidence they find, getting the evidence photographed in its place, and then scooping it into a bag. [Creed and Newman, 2008, pp. 180] Arlington police officers, military personnel, and others also participate in the search. [Goldberg et al., 2007, pp. 159] They also look for evidence across grass and roadways several hundred yards from the Pentagon. [PBS, 9/12/2001] Some pieces of the aircraft that hit the Pentagon are found nearly 1,000 feet away from the building, on the other side of Washington Boulevard. Thousands of tiny pieces of aluminum have also carried forward over the Pentagon, into its center courtyard. Other pieces of debris landed on its roof, along with body parts from at least one victim. [Creed and Newman, 2008, pp. 29] According to the Defense Department’s book about the Pentagon attack, the searchers find “many scraps and a few personal items widely scattered on the grass and heliport. Plane remnants varied from half-dollar size to a few feet long.” [Goldberg et al., 2007, pp. 159] Authors Patrick Creed and Rick Newman will describe: “Agents found what looked like a big Plexiglas windowpane on the lawn, which might have been part of an airplane window, except it was too big.… Somebody suggested it could be one of the blast-proof windows from the Pentagon, somehow blown 500 feet from the building.” [Creed and Newman, 2008, pp. 180]
