Woodbridge , Virginia ( CNN ) -- Ballistics test results link four shootings at U.S. military facilities in the Washington suburbs in October , and investigators are probing whether a new case at a Coast Guard recruiting office is related , police in Virginia said Tuesday . The latest incident was reported Tuesday morning after a bullet struck the recruiting office , housed in a Woodbridge strip mall . The description is `` relatively similar '' to October cases in which shots were fired at the Pentagon , the National Museum of the Marine Corps and a vacant Marine recruiting station , said 1st Sgt . Kim Chinn , spokeswoman for Prince William County police . `` Employees of the Coast Guard recruiting station called to tell us there was some damage to the glass , and police arrived and determined it was probably done by a bullet , '' Chinn said . She said the shooting left a mark on the glass . `` It did not penetrate the glass , more like a graze , '' she said . No one has been injured in any of the incidents , which include one in which six shots were fired at the Pentagon early on October 19 . Ballistics tests have connected that incident to shots aimed at the Marine museum on October 17 and 29 , as well as to an October 25 case in which shots were fired at a Marine Corps recruiting station in Chantilly , near Washington Dulles International Airport . Chinn would not say how many bullets were found at the scene Tuesday . The Coast Guard referred questions to the FBI , saying it is taking the lead in the investigation . The FBI said it has sent personnel to the recruiting center . The Pentagon Force Protection Agency has declined comment on the shooting . CNN 's Brian Todd , Adam Levine , Padma Rama , Mike Ahlers and Carol Cratty contributed to this report .
Ballistics link 4 previous attacks on military facilities . Comment: A bullet struck a window at a Coast Guard recruiting station Tuesday .