Lopez had not been diagnosed with Post Traumatic Stress Disorder, but he was being evaluated to see if he had it.
"There may have been a verbal altercation with another soldier or soldiers and there is a strong possibility that that in fact immediately preceded the shooting," said Ft. Hood Commanding General Lt. Gen. Mark Milley.
The U.S. Department of Veterans Affairs estimates that PTSD occurs in about 11-20% of Iraq and Afghanistan veterans.
For more information about PTSD, visit the VA website at ptsd.va.gov.
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