Murder / suicides that kill complete strangers, like the police officer in the Virginia Tech recent shooting, or the apparent relative stranger in this case, are more problematic to explain.
The answer would seem to me, given how tragically many of these we have, with multiple incidents of murder / suicide every week, that in part the weapon of choice in the overwhelming majority of these incidents to be firearms.
We know that in suicides where there is no additional killing of other people, that firearms present a very different attraction than other means of killing oneself. Firearms have been identified as leading more people to commit suicide or attempt suicide than would otherwise do so; it is a weapon of impulse. In many of these murder / suicides there is a pattern of either some precipitating event or occurrence, or in many -- including this one --- the use of some substance, most often alcohol, but sometimes other impulse control altering drugs that suppress that center of the human brain, which impair the person's ability to control their impulses. We do know from the information available about THIS murder / suicide that the individuals involved had been out partying in bars for a number of hours immediately prior to the mass shooting.
The question has been raised about this case, weren't these pilots given extensive psychological testing. Presumably they were, before the Marine Corps. invested so much in their training, and before they were trusted to fly our expensive war planes. I expect that future updates may very well address what kind of testing is involved.
But until that specific information is available, from this and from all of the other cases, it IS clear that the combination of substances which suppress or inhibit human impulse control, combined with the temptation to use a lethal weapon noted for being an impulsive choice in killing people is a tragic combination.
In other countries, the occasional murder / suicide still happens. But the fewer firearms per capita, the fewer of these murder / suicides per capita occur. They become rare events, not multiple weekly occurrences. The use of alcohol (or drugs) that reduce impulse control, absent impulsive deadly firearms, result in far fewer killings by substituted means.
This reflects the uniquely dangerous aspect of firearms that result in this weapon, unlike others, being tragically used so very much more often. Unlike the detection of dangerously mentally ill people who are paranoid schizophrenics, people like Jared Loughner and Anders Breivik, who commit mass shootings, psychological testing would probably NOT screen out all of these killers. It might screen out some of the more clearly unstable individuals, but not all.
Far fewer firearms however WOULD dramatically reduce if not entirely eliminate these incidents. It is the weapon of choice that is most often involved that is part of the problem, and the key to the solution of preventing these events: fewer guns, NOT more guns.
Disturbing comments by Navy pilot in murder-suicide emergeA Navy "Top Gun" pilot behind a New Year's Day murder-suicide in Coronado, Calif., left behind disturbing commentary about himself on social network sites, including a post that read "I unintentionally screw people over on a regular basis," a San Diego television station reported.
Police say John Robert Reeves, 25, shot three people and himself inside a condominium after an evening out at a nightclub with the group. Fellow Navy pilot David Reis, 25, was killed by a gunshot wound to the torso, and his 24-year-old sister, Karen, was shot in the head and chest, officials said. Matthew Saturley, 31, of suburban Chula Vista, was shot multiple times. Reeves and David Reis were at the top rung of training in the Navy's elite "Top Gun" program.
Friends spoke out on behalf of Reeves on Saturday, describing him as a focused and reasonable young man.
"This is all very, very bizarre," Josh Buck of Port Republic, Md., told NBCSanDiego.com. "This is so uncharacteristic ... it is hard to believe what everyone is saying."
See video at NBCSanDiego.com
Another friend, Shane Cameron, also of Maryland, said his last converation with Reeves was upbeat and optimistic.
"I was asking him how his training was going and he seemed to be happy and loving it," Cameron told the NBC News affiliate.
The men said Reeves was looking forward to his future.
But news reports about Reeves's online postings in several discussion groups painted a different picture.
According to 10news.com, Reeves's posts included:
"I might come across as a nice guy, but I unintentionally screw people over on a regular basis."Clinical psychologist Dr. Michael Mantell told 10news.com that Reeves' posts, some of which used profanity to describe himself, raised disturbing questions about his mental health and whether he thought of himself as a loser. "Other people are writing to him, saying, 'Doesn't the Navy have psychological screening?'" Mantell noted.
"I'm brutally honest."
"Whenever I try to do something nice to help people out, it goes horribly wrong, and everyone would have been better off if I just kept to myself."
Investigators say they may never know what motivated Reeves to open fire on the gathering inside the condo he shared with Reis and another pilot who was not present. They say jealousy may have placed a role.
"We only know it's tragic," San Diego County Sheriff's Department Captain Duncan Fraser told Reuters earlier in the week.
Reeves, of Prince Frederick, Md., was commissioned in the Navy through the Penn State University Reserve Officer Training Corps in 2008. He was a F/A-18 pilot assigned to the Marine Fighter Attack Training Squadron 101 based out of the U.S. Marine Corps Air Station Miramar.
He had been awarded the National Defense Service Medal, a standard commendation given upon completion of basic training.
This post includes reporting from NBCSanDieog.com, Reuters and msnbc.com's Sevil Omer.