The man blamed for triggering a terror scare at the Pentagon and Arlington National Cemetery last Friday has been linked to a series of shootings that targeted military locations in the Washington, D.C., area last fall.
Preliminary forensic evidence appears to tie Yonathan Melaku to at least one or two of the five shootings, ABC News has learned. But the forensics, which sources say are ballistics evidence, remain incomplete.
The shootings last fall targeted the Pentagon, the National Museum of the Marine Corps twice, a Marine Corps recruiting center and a Coast Guard facility in Virginia.
At the time, the FBI said it suspected the shooter was a disgruntled military man. Melaku is a Marine reservist.
"We believe this suspect has a grievance surrounding the U.S. Marine Corps," John Perren, then the acting assistant director of the FBI's Washington field office, said of the shooter in October 2010. "We'd like to know what this grievance is and what we can do to try to help solve it."
The military shootings began Oct. 17, 2010 at the National Museum of the Marine Corps, when someone fired at least 10 bullets into the building's ceiling.
Two days later, six or seven shots were fired at the Pentagon, shattering windows.
Then, on Oct. 26, shots were fired at a Marine Corps recruiting center in Chantilly, Va.
The shooter struck a second time at the Marine Corps museum on Oct. 30, then hit a Coast Guard recruiting station in early November.
All the incidents occurred in the middle of the night and nobody was injured. The shots appeared to target buildings, not people, and nobody has been charged with the shootings.
Melaku, a 22-year-old Ethiopian native, was arrested in the early-morning hours Friday in Arlington National Cemetery after he ran from a police officer on patrol. Police found three shell cartridges and baggies containing a substance that appeared to be an explosive in his backpack.
Authorities feared he may have been targeting the Pentagon and the nearby Marine Iwo Jim Memorial. The resulting investigation shut down traffic around the Pentagon and Arlington National Cemetery for hours Friday morning, snarling morning rush hour traffic.
Spokespeople for the FBI Washington field office and U.S. Attorney's Office said the investigation is ongoing investigation and would not comment further.
Melaku is jailed in Loudoun County, Va., on theft charges related to auto break-ins in Leesburg, Va., earlier this year.