I received an automated message on Sunday that there will be enhanced security at my daughter’s elementary school. The doors to the school are already locked, requiring someone in the front office to buzz visitors in. The school will now no longer grant admittance to any unannounced visitor, even a parent. Any visitor must call or write ahead of time with the time and purpose of their visit.

This is fine, and probably a reasonable security policy for a school, but it would not have stopped the shooter from carrying out the horrific killings that took place four days ago in Newtown, CT. The killer apparently shot his way into the school.

It’s difficult to process the events that occurred in Sandy Hook Elementary School. A 20 year old gunman entered the school with an assault rifle, large capacity clips, with hundreds of total rounds, and two additional pistols. He went to the principal’s office and killed everyone there, then proceeded to classrooms to kill as many children as he could. (Correction – the news report now is that the principal, Dawn Hochsprung, went to investigate the gun shots and was killed while rushing the shooter.) In the end he killed 20 children, all aged 6-7, and 6 adults. This was after shooting and killing his own mother at home. The gunman’s last victim was himself, committing suicide when his spree was done (it’s possible he killed himself when he heard the sound of approaching sirens).

I understand the emotions of such an event. I am a parent, and one of my daughters is still in elementary school. This scenario is every parent’s unthinkable nightmare. We send our kids off to school and trust they will be safe.

This one is also physically close to home. My parents and two of my brothers live in Sandy Hook. A close friend of Evan’s (an SGU co-host), someone I also know, was a first responder, has kids in the school, and his wife was at the school during the shootings. (Here is an interview where they tell their story.) It doesn’t make the events any more horrific, but it feels closer. This happened right next door.

The temptation when such events occur is to immediately start speculating, and in some cases drawing conclusions, about what and who is to blame. Everyone wants to put their own ideological spin on what happened and how to prevent it from happening again. The common themes have been – gun control, mental illness, video-game violence, and even the media (giving attention to the shooter, making it more attractive for the next would-be shooter).

All of these issues certainly deserve attention, I just don’t think we should be jumping to any conclusions. We do not yet have enough information (at least it hasn’t been made public) about the situation. The current information is that the gunman took the guns from his mother, who owned them legally for target shooting. This raises many issues, but let’s sort through them thoughtfully.

There seems to be some low-hanging fruit when it comes to gun control, even without this latest incident. I do think that the burden of argument is on gun proponents to justify why a private citizen, using guns for target practice, hunting, any sport or even personal security, needs to have a large-capacity clip that can hold more than 30 rounds, or an assault rifle designed for military applications. I am all for responsible gun ownership, but there are some reasonable measures to consider.

There is a question, however, of the net effect of gun regulation measures. The data is messy with many variables that are not well accounted for. There is data that informs the discussion, it’s just not definitive. For example, following the 1996 assault rifle ban in Australia there was an increase in the rate of decline of gun-related homicides. On the other hand, a study of various gun regulations across the 50 states in the US showed no statistically significant difference in homicides (there was a trend, but not statistically significant). There are enough studies for people to cherry pick the data that supports their position. I don’t want to make this an article on the complex question of gun control – I just want to make the point that it is reasonable to address this issue, the discussion should be evidence-based, we currently need more and better evidence, meanwhile we can make some rational decisions based on the evidence we have.

We do not  yet know anything official about the shooter’s mental state. Did he have a formal diagnosis, any recent psychiatric care or assessment, any triggers that might have caused this rampage? Were there warning signs that should have been recognized? How predictive are they, and what options are there for dealing with potential violence of this type?

I have seen some discussion of whether or not anyone who could stare down a room of 7 year-olds and then riddle them with bullets could be considered sane. This is an interesting question, and of course depends on the definition of sanity (which is a spectrum, not a bright line). I don’t think we should throw around any diagnoses based upon the little and imperfect information trickling through the media. Clearly, however, the shooter was in a very extreme mental place that is difficult for most people to imagine.

With this issue also there is data to inform the discussion. There is an association between homicide and mental disorders. According to one study 15% of all homicides are committed by someone with a diagnosis of mental disorder. Among homicide offenders, 6% have schizophrenia, 10% have a personality disorder, and 38% have alcohol abuse/dependence. The combination of paranoid schizophrenia and alcohol abuse is a significant predictor of the risk of homicide, but the highest is the association of antisocial personality disorder and alcohol abuse.

While there is an association, we have to remember the other side – 85% of homicides are committed by people without a diagnosable mental disorder, and most people with a mental disorder do not commit violent crimes.

In any case, we do need to evaluate (incidental to this latest episode) if there are sufficient resources for those with mental illness. The community-based system we currently have is chronically underfunded, leaving many people who need help without it.

The video-game issue seems like the biggest red-herring to me. This is pure speculation, not based on any information about the shooter. Here again we have a research literature to look to. A recent review concludes:

“Overall, the evidence supports hypotheses that violent video game play is related to aggressive affect, physiological arousal, aggressive cognitions, and aggressive behaviours.”

However, the literature does not establish cause and effect. It may be that people with aggressive tendencies are drawn to violent video games.

All of the above research relates to violence and homicide in general, not to school shootings or dramatic spree killings like what happened in Sandy Hook. Such events are thankfully rare (although not rare enough). There are therefore more variables than data points, and there is simply no way to generate reliable data about what causes such extreme events.

We can inform discussion of how to respond to Sandy Hook and other similar events with the research data we have, while trying to fill gaps in that data. But we will have to make policy decisions in the absence of adequate data (at least for the foreseeable future) to draw firm conclusions about what causes such events, how they can be predicted, and how to prevent them. In a free society there is simply no way to completely prevent such acts of violence, but we certainly should search for every feasible way to minimize them.