The Marine who shot two of his colleagues to death and then killed himself has been identified as tactics instructor Sgt. Eusebio Lopez.

Military officials made the announcement that it was Lopez, 25, who gunned down 19-year-old Lance Cpl. Sara Castromata and Cpl. Jacob Wooley, 23, on Thursday night inside barracks at the Marine Corps Base Quantico in northern Virginia.

When the statement was made Saturday military officials did not describe Lopez's relationship to the two victims other than that the three worked together. No motive for the shooting was mentioned either.

Lopez was a tactics instructor at a school that tests Marines who want to become officers.

A Pacifica, California native, Lopez's specialty was machine gunner. He joined the corps in May 2006 and deployed in support of the wars in Iraq and Afghanistan.

Castromata, of Oakley, Calif., was a warehouse clerk who had been in the Marines since December 2011. Wooley, of Guntown, Miss., was a field radio operator. He joined the Marines in February 2010.

Lopez was an instructor at officer candidates school, known for its grueling 10-week program that evaluates Marines on physical stamina, intelligence and leadership. The candidates must cpmplete obstacle courses, hikes of up to 12 miles in full combat gear and take classes on navigation and tactics that help them in the field, according to the school's website.

Lopez's great-grandfather, also Eusebio Lopez, said the Marines contacted their family on Friday night.

"They told us they were investigating more, and they'd let us know. He wasn't the type to do stuff like that," said Lopez, 81.

Based on reporting by the Associated Press.

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