“It would probably be best for the military if they could execute Bales right now and send his pieces to Afghanistan.” That’s what National Veterans Foundation founder Floyd Meshad told me this week while we were talking about Staff Sergeant Robert Bales and the insanity or diminished-capacity defense Bales’s attorney apparently intends to use. Bales was formally charged today with slaughtering 17 Afghan civilians earlier this month in Kandahar.

With the politics, with the foreign relations involved, with the exceptionally high bar for proving lack of mental responsibility in military courts, it’s likely Bales is going to end up taking sole responsibility for his actions in the upcoming trial. Which is too bad. Does this case involve war crimes of the highest and most horrific order? Absolutely. But was it all Bales’s fault? Probably not so much. Not given the chain of command that put him in a position to suffer such extreme levels of post-traumatic stress.

There’s something of a frenzy of PTSD-research stories in the media this week. Did Bales have PTSD? Can PTSD make you act “insane”? What is the link between PTSD and traumatic brain injury (TBI)? How strong is the link between PTSD, traumatic brain injuries, and violence? Is it strong enough?

Of course, there’s no totally definitive extent to which any of these tricky neurological and psychological queries can be “proved.” What we do know: that Bales served four tours of duty; that Bales was treated for TBI; and that traumatically injured brains do not operate like regular brains — because of altered cognitive functions, inconsistent memories, and the ease with which they’re overwhelmed, irritated and angered.

A lot of service members overcome their injuries and disorders, and reintegrate into their lives — bless their outstanding resilience. And very, very few have ever done something so abhorrent. But “as far as soldiers with PTSD going off the deep end, there’s no doubt that there’s a correlation,” says Meshad, who was a mental health officer with experience extracting soldiers who’d “snapped” in Vietnam. After decades of treating, and being consulted for criminal trials involving, veterans with PTSD, he literally wrote the book on defending them. Obviously, most veterans with PTSD don’t commit a crime. But attorney Brockton Hunter, who specializes in PTSD defense and co-wrote the Attorney’s Guide to Defending Veterans in Criminal Court with Meshad, says that “historical research confirms waves of veteran-committed crimes after every major conflict.” The U.S. Army’s own 2009 study of a rash of violent crimes at Ft. Carson, Colorado, found a correlation between the number and intensity of soldiers’ deployments and “negative behavioral outcomes.” Hunter says: “In other words, the more you see, and do, in combat, the more likely you are to be affected by it and to act out in bad ways.”