Ballistics testing has officially linked allin the Washington, D.C., area, reports CBS News Correspondent Bob Orr.
Evidence connects a shooting overnight Monday at a Marine Corps recruiting station in Chantilly, Va., with the same gun used to shoot at the Pentagon and the National Museum of the Marine Corps in Northern Virginia earlier this month, the FBI said.
No one was injured in any of the shootings.
A statement from the FBI issued Tuesday said officials are withholding information about the make and model of the gun and the type of ammunition used "to preserve the integrity of investigative efforts."
Law enforcement sources said the incidents do not seem to be connected to any threat, and it seems the shooter or shooters are making no attempt to target people because all of the incidents have happened in desolate early morning hours, Orr reports.
Early on Oct. 19 shots were fired overnight into two windows at the sprawling Defense Department across the Potomac River in suburban Virginia. Two days earlier, bullet holes were discovered in the windows at the National Museum of the Marine Corps in Triangle, Va., 30 miles south of the Pentagon.
Federal investigators were at the recruiting station in Chantilly Tuesday, "trying to link anything they can to what has already been proven," said Lindsay Godwin, spokeswoman for the FBI's Washington field office.
Marine Museum officials said that building had been hit by at least 10 rounds. Gwenn Adams, a museum spokeswoman, said last week that officials at the museum, which is associated with the Quantico Marine Base, did not receive any threats or warnings before the shooting.
On the morning of the Pentagon shooting security officers heard five to seven shots about 4:55 near the south parking lot. Bullet fragments were later found lodged in two windows of unoccupied offices on the third and fourth floor.