(RNN) - The mental health of a soldier who allegedly killed three at Fort Hood on Wednesday was not the "direct precipitating event" in the shooting.
Fort Hood Commander Lt. Gen. Mark Milley said an argument might have lead to the incident, which also injured 16.
"There was no premeditated targeting of individuals. There was an argument, it escalated," said Milley.
After the shooting, Army Spc. Ivan Lopez turned the gun on himself at one of the largest military installations in the country.
Lopez was being treated for an unstable mental condition before the shooting, according to Milley.
"Given that the alleged shooter is deceased, the possibility exists that we may never know why he did what he did," said Chris Grey with the U.S. Army Criminal Investigation Command.
Lopez entered active duty in June 2008 and was previously assigned to Fort Bliss, TX. He arrived at Fort Hood in February.
The identities of the three soldiers killed were released Friday. The soldiers are Sgt. Danny Ferguson, Sgt. Carlos A. Lazaney and Sgt. Timothy Owens.
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