The FBI has confirmed that the same weapon was used in three recent incidents: one shooting more than a week ago at the Marine Corps Museum in Triangle, Va., one two days later at the Pentagon, and one earlier this week at a vacant Marine recruiting station in Chantilly, Va. The FBI is still trying to confirm that a fourth shooting Friday morning is connected.
"All three shootings prior to [Friday's] shooting had the USMC [Marine Corps] as a common link," said the note, issued by the U.S. Army's Criminal Investigation Command to other parts of the military. "We cannot discount the three incidents as being a warning to the USMC to not run the marathon."
