Seems like nearly all tragedies involving guns and other tragedies: the person had some underlying mental health issues and were not making (obvious) rational decisions. Some crisis, pushed over the edge...not in their right mind. Like teens being mercilessly bullied at a difficult (high school) period in their lives.
An interviewed neighbor had a telling encounter with Travis (and seems to have met Travis several times before):
A neighbor shared details of a "weird" encounter with Travis Decker on the day he picked up his daughters.
www.fox13seattle.com
I feel he took himself out after what he did. Unfortunately, we may never find evidence, if that is the case. He probably went up into the hills and animals took care of his remains in the "circle of life." I think he went absolutely into a very dark place, beyond his control, and committed an unfathomable act that is incredibly heartbreaking.
We can't deny that marijuana iits been documented to have adverse effects in some people. However, it is a substance that can make things worse (or better) for people. For me, I make edibles and its the only thing that helps me sleep in all my years.
One thing I find odd, all these months later, is lack of interviews or information on his military days (former comrades) or his family - parents, brothers, sisters. It just seems like there is so much missing information, but may be held close to the vest, by law enforcement, to protect their case. I would have thought someone would have sought out and talked to people who knew him well and reported that.
It does appear in the link above that he sought help from the VA and a chaplin (mentioned in another article), but it was simply not enough to help him. He knew he had a problem, which is quite sad. Sometimes it takes involuntary commitment of an individual to help that person, but something that is rarely ever invoked. (Like a guy interviewed in another story about being on drugs and living on the streets - if he hadn't been locked up for treatment, he's still be out there on the streets doing what he did.)
It's pretty brave in the military to speak up, seek help, as the military can seem vindictive (it seems on the surface) toward its members. I remember in the military that people that had problems were used as an example and dealt with. Like the Japanese saying: the nail that sticks out, gets the hammer. People do keep their problems to themselves if they feel that saying something will have adverse effects on their carrier and have a little note or two in their personnel file to call into question their capacity to serve. And used for promotions, which are necessary if you wish to continue in the military for a long period of time.
There's also the crimes of passion committed by people. This doesn't appear to fit that narrative. He had a crisis beyond his control, whether or not a substance induced or aided in his act.