Investigators are still trying to figure out a motive for the shooting death of America's top sniper, Chris Kyle and his friend Chad Littlefield. Both were shot to death last weekend at a shooting range in Texas. The suspect is a fellow veteran, Eddie Ray Routh.
Local Vietnam veteran Steve Penner believes the shooter likely suffers from post-traumatic stress disorder.
Penner told NewsChannel 3, "I just think oh my gosh, another guy who had a bad experience, who saw a lot of combat, who just came home and didn't know how to deal with it."
Over the last decade, some 70,000 service members have been diagnosed with PTSD.
Former Marine Derek Coy told ABC News, "I was constantly feeling anxious, I constantly felt like something bad was going to happen."
Penner says military members and their families need to be more vigilant about recognizing signs of trouble and to get help.
"It's like having a nervous breakdown and not getting over it, Penner said. "It can go on for years and years. You can have it the rest of your life."
Penner, who is a lawyer, says the criminal justice system is doing more to address the needs of veterans who have a hard time adjusting to life after combat. Santa Barbara County now has a veterans court.
Penner told NewsChannel 3, "it is a great program where veterans who do get into trouble with the law because of PTS(D) are treated differently, appropriately. Now, the justice system is treating them with more of a restorative justice than punishment justice."
It's still too soon to know if PTSD was a factor in the killings of Kyle and Littlefield, but officials say it's a problem the military needs to know more about.