Pentagon officials announced new security measures on Thursday that include more random screening of visitors and Defense Department workers, a wider security perimeter and more lighting around the building's main entrance, after a shooting incident there last month that left the gunman dead and two police officers injured.

The changes will be most noticeable at the busy southeast side of the building near the Metro station, according to the Pentagon Force Protection Agency, which has installed more lighting and positioned police officers closer to the station's escalators.

"We've had a lot of things in place here since 9/11, but the March 4th incident and other incidents have caused us to really look at this," PFPA Director Steven E. Calvery said in reference to the March shooting and last year's massacre at Fort Hood, Tex., in which 13 people were fatally shot.

"I think it sends a message to everyone what you can and can't do here," Calvery said.

A temporary screening center for visitors also will be constructed at the Metro entrance this summer before a larger structure is built in the coming years. The construction is part of a multimillion-dollar revamp of Pentagon security that includes a new hazmat response center, a new truck screening facility, and more security sensors and lighting across the sprawling complex.

About 23,000 Defense Department employees and contractors work at the Pentagon, which receives more than 1,000 visitors a day, according to PFPA. With Metro rail and bus passengers, the agency said, 50,000 to 60,000 people, on average, pass through the Pentagon complex on workdays.

George W. Bush's administration established PFPA in 2002 in the wake of the Sept. 11, 2001, attacks. It employs 1,300 workers, including about 750 police officers.

John Patrick Bedell, 36, opened fire near the Pentagon entrance on the evening of March 4 and later died of gunshot wounds to the head. Officers Jeffery Amos, 46, and Marvin L. Carraway Jr., 44, sustained minor injuries in the shootout. Both officers reported to work Thursday, the agency said.