The Marine Base Quantico, spokesman Lt. Agustin Solivan briefs reporters following a shooting incident on the base Friday March 22, 2013. Three people, including the suspect, were killed in the shooting at Marine Base Quantico, Solivan said early Friday. He said they believe the suspect, whose name wasn't released, is a staff member at the officer candidate school at the base. No information on the victim was immediately released. (AP Photo/Matthew Barakat)Via Ian Simpson WASHINGTON (Reuters) – A Marine shot useless a female and male colleague at a Virginia base and then killed himself, within the second fatal non-combat incident involving Marines in the United States this week. Defense force investigators declined to comment on what influenced the taking pictures late on Thursday, which led to a 3-half of hour lockdown of Marine Corps Base Quantico that prolonged to the pre-first light hours on Friday. The shooter and his victims have been college staff members and lively-duty Marines, base commander Colonel David Maxwell said on Friday. …