Today, newspaper headlines informed us of another tragic shooting at Fort Hood, Texas. Ivan Lopez, an Army truck driver bought a 0.45 caliber Smith & Wesson semiautomatic handgun and murdered 3 and injured 16 military personnel on the base. He had purchased the weapon a couple of days before the shootings but had not registered it with base authorities as is required.
He purchased the weapon at the same firearms store where Maj. Nadal Hassan had purchased his before he opened fire in a medical facility on base. However, Ivan Lopez did not have a history to suggest that he was not competent to purchase a firearm. He had no prior history of violence.
This tragic event ended in suicide. Lopez turned the gun on himself when confronted in a parking lot by military police. At this point we do not know what led to this tragic murder and suicide.
CNN reported this morning on statements made by the Army Secretary who explained that Lopez had two deployments, but there was no record of injury or direct combat. Apparently, Lopez had complained that he suffered a traumatic brain injury while deployed, but it is unclear how this could have happened. It is known that he was under treatment for depression, anxiety, and sleep disturbance for which he was prescribed Ambien (sleeping pill).
There was no evidence that he was likely to harm himself or others. The Army Secretary is quoted as saying that he had a "clean behavior record."
It has been reported that he saw a psychiatrist during the prior month and he was being evaluated for possible PTSD. What event he could have experienced or seen that might have caused PTSD has not been described.
One thing this case demonstrates is just how challenging it can be to predict violence. We can look for risk factors such as a history of violence, but there is no definitive way to know. It may be tempting to blame his depression and anxiety, but the overwhelming majority of people with these conditions are not violent. They are far more likely to harm themselves (suicide) than to hurt anyone else.
It may also be tempting to blame Ambien since is is known to rarely cause complex motor activity while in a sleep state and have no recollection the next morning. It is suspected when evidence is found that someone made a sandwich during the night or his car had been moved. However, this is not a tenable explanation since these sleep-associated actions are not characterized by this type of violent behavior. Furthermore, since Lopez purchased the gun a day or two before he opened fire on innocent people, he almost certainly planned the attack in advance, which is not consistent with his medication to be blamed.
Speculation about PTSD playing a role has also arisen. At this point it is not known if he had PTSD, especially since he did not see combat when deployed. Furthermore, although anger is a characteristic symptom of PTSD, it rarely results in serious injury to others.
Although it seems highly unlikely that PTSD played a role in this instance, it is interesting to know the connection between PTSD and violence. Most instances (35.9% of veterans in one study) were associated with a combination of PTSD and alcohol abuse. In contrast, only about 10% of veterans with PTSD alone had a history of violence during a nine month timeframe. The rate of violence in veterans without PTSD or alcohol abuse was only 5.3%. (Elbogen et al Br J Psychiatry Feb 27, 2014).
It is important to emphasize that violence among patients with mental illness is unusual. It is also important to note that we do not really know any meaningful details regarding what mental illness Lopez suffered from. We also do not know what led him to commit mass murder. Please see my previous blog on mass murder for more information on this topic.
Peter M. Hartmann, MD
Family Medicine & Psychiatry
