According to Washington D.C. Mayor Adrian Fenty, the inauguration of President-elect Barack Obama in January could draw record crowds. Fenty is predicting anywhere from 3 million to 5 million for the inauguration and surrounding festivities.

In anticipation of a record turnout, security preparations are already well underway to ensure that the historic ceremony goes off without a hitch. In fact, in a recent AP story, Washington D.C.’s police chief, Cathy Lanier, said that her department has requested an additional 1,000 officers on top of the 3,000 it typically requests from law enforcement agencies across the country to assist with the inauguration. Over at the Washington Metropolitan Area Transit System, officials have made plans to temporarily close select stations for security reasons during the inauguration and to hold some trains until the presidential motorcade has already passed over those transit tunnels.

One man who is accustomed to protecting presidents and other dignitaries during large-scale events is former U.S. Secret Service Agent Bill Warren. Warren, who now runs Vectra Security Service, a security consulting firm in Atlanta, Ga., spent more than 20 years with the agency. Prior to joining the Secret Service, Warren served seven years in the U.S. Air Force working with the White House Communications Agency, which provides communication support to the office of the president.

Working primarily with the technical security team during his time with the Secret Service, Warren knows the types of challenges that authorities face in trying to keep the president-elect safe, having helped secure the inaugurations of presidents Nixon, Carter, Reagan, Clinton, and George H.W. Bush. Warren is also experienced in the realm of private security, having headed up the security department at the Georgia Tech Research Institute following his career with the Secret Service.

In this “At the Frontline” interview, Warren shares his insights on dignitary protection and what the projected turnout of people holds for Secret Service agents and other authorities charged with keeping the inauguration safe.

What types of preparations go into security for a presidential inauguration?