On June 12, 2016 fifty people died in an Orlando Nightclub. 49 of these were victims of the 50th, who has been identified as Omar Mateen. This is the latest and the largest mass shooting in the United States. As always happens in such cases, there are inquiries into motives and, most importantly, into how such a slaughter was able to take place.
Mr. Mateen, the alleged shooter, was a 29 year old American who worked for the G4S security company. It has been claimed that he committed domestic violence against his then wife (although no charges were apparently filed), that he spoke of his hatred of blacks, gays and Jews, and a coworker has alleged that he often spoke of wanting to kill people. He was investigated by the F.B.I. in 2013 and 2014 in regards to suspected connections to terrorism. These investigations failed to yield adequate evidence for action to be taken against him and he was able to legally purchase the weapons used in the attack.
This mass shooting, like others before it, give rise to an important epistemic question: how can we know when a person will become a mass shooter (or terrorist)? While it is certainly tempting to infer that expressions of hate and expressed desires to engage in violence are good indicators, they are not. A little reflection and a little time on the internet show that hate is abundant as are expressions of desires to engage in violence. The vast majority of these people never make the move from expression to mass shooting. As such, while this sort of behavior is an indicator, it is a very weak indicator. What would be needed would be clearer evidence that a person is preparing to go from thought to action.
It might be believed that signs of connection to terrorism (such as expressing support or having some personal ties to terrorists) are good indicators. While this is also tempting, there are many who express support of terror (be it for ISIS or for using terror against minorities, women, LGBT people, etc.) yet never escalate from expressing support to murdering. There are also people who have personal ties with terrorists who themselves never become terrorists—in fact, these people include some who condemn terrorism. As such, what would be needed is clearer evidence that there will be a transition from support or connections to violent action.
It could be claimed that there was adequate evidence Mateen was going to become a shooter and the F.B.I. failed in its investigation. This is, of course, a factual matter and one that would be addressed by investigating the investigation. While some might be inclined to believe that the F.B.I was sloppy or incompetent, it seems quite likely that there simply was not enough evidence to justify taking action against him. As it stands, this seems to be the case, despite Mateen allegedly calling 911 to express his loyalty to ISIS (and a mishmash of other groups that actually oppose each other). While ISIS has been happy to claim Mateen’s expression of fealty, this seems to be an affiliation of opportunity: there is currently no evidence that ISIS directed the attack nor evidence that Mateen had any substantial prior connection with ISIS. As such, the best hypothesis at this time is that Mateen was seeking to transform a hateful mass murder to a hateful mass murder for a cause and that ISIS was once again happy for the gift of blood.
It could be asserted that action should be taken against people who might engage in a mass shooting or who might become terrorists. In the case of Mateen, it could be claimed that the F.B.I. should have acted against him even without adequate evidence. This is where the discussion switches from epistemology (what can be known) to morality (what should be done).
The matter of determining the level of warranted suspicion that justifies taking action against a person is a rather important moral concern. On the side of public safety, the stock argument is that by acting on a relative low threshold of warranted suspicion, the public is kept safer. This is a stock utilitarian argument in which the morality of an action is a matter of weighing the harms against the benefits. In the case of Mateen and others, the claim would be that if action had only been taken on the basis of the available evidence, then the murders might have been averted. As a specific example, if expressing hatred of the sort linked to mass shootings resulted in a person being legally banned from owning guns, then there would be less likelihood of a mass shooting occurring. As another example, if the state could detain people on the basis of limited evidence of connections to terrorists, then terrorist attacks would be less likely to occur because more possible terrorists would be locked away (perhaps without trial).
On the side of liberty, the stock argument is that acting on a relatively low threshold would violate rights and create more harm than safety. This is also a utilitarian argument; the difference being in the assessment of harms and benefits. For example, supporters of the Second Amendment such as the NRA would be quick to claim there would be terrible harms and dangers of being able to deny people their gun rights based on the mere expression of hatred or a mere suspicion a person is going to engage in a mass shooting. In fact, the usual claims are being presented that the shooting could have been prevented or mitigated if only more people had guns.
As another example, those who support the idea of having to show guilt beyond a reasonable doubt would oppose such a low threshold of detention for suspicion that a person might engage in a mass shooting. These would tend to be people who respect the idea of the rule of law (though law can be made awful).
It can even be argued that such a low threshold policy would make the public less safe: the violation of rights and low-threshold detentions would create anger and resentment that would lead to more and not less harm. My own position is in opposition to a low threshold—the cost is not worth the gain (if any) of such an approach. In regards to the gun regulation debate that the murders have ignited (once again), I really have nothing new to say about guns—nor, does it seem, does anyone else.