ShotSpotter Blog

Proactive Policing - It’s in the numbers

Like many businesses and industries, law enforcement today is challenged with how to do more with less. We believe ShotSpotter can be a “force multiplier” and help law enforcement do more with less, especially in the proactive battle against gun violence. Departments that have deployed ShotSpotter are able to leverage its critical, real time gun fire alert information for more effective, precise AND impactful resource allocation.

Many city leaders and police chiefs who I encounter have gun violence issues which they desperately want to address, but “believe” they cannot take advantage of ShotSpotter. They are concerned that if less than 20% of illegal gun discharges is reported via conventional means of a 9-1-1 call for service that the potential 5X ShotSpotter alerts will overwhelm their limited resources.  Their latent fear is that they will miss-set community expectations of response times that they will be unable to meet. On the surface 5X the awareness and accountability (although not necessarily the actual gunfire-as it is happening) seems daunting.

In fact, when you do a deeper dive on the data from various ShotSpotter deployments you see the opposite is true. Agencies and the respective communities they serve are greatly benefiting from the enhanced response efficiency of getting a real time, location precise alert with almost zero false positives vs the one-off “I heard shots fired somewhere out there” call. 

We compared three ShotSpotter cities – one in the West, one in the Southwest, and one in the Midwest to gain some insights into the force-multiplier question. These three cities have ShotSpotter coverage areas ranging from 3.2 to 11.8 and 12.8 square miles, and all have populations of 500,000-700,000. The data shows that all three cities have roughly one-third of their total activations taking place during the three eight-hour shifts of Thursday/Friday/Saturday from 8pm-4am. The activations average from 3.7 to 5.4 and 7.9- per weekend and, respectively, represented a range of 38.4%, 32.1% and 37.1% of all of their activations.

When you then consider the average activations per square mile for these cities you can build a pro-forma case for a hypothetical city deployment. Assuming 500 to 1,000 ShotSpotter alerts per square mile per year, a five square mile deployment would generate 2,500 to 5,000 activations total per year. At first blush this might appear to be overwhelming, compared to the usual 500-1,000 9-1-1 calls generated given the 20% or less under-reporting issue. However, when our rule of 33% distribution of activations over the 8pm to 4am weekend period is applied, the “art of the possible” becomes clearer. Our hypothetical city would generate 900 to 1,800 activations per year over those three shifts or even better −17 to 35 activations per weekend.

Therefore, what law enforcement would need to do in our hypothetical city is be able to organize and resource themselves to respond to 17 to 35 activations per weekend. Not a heavy lift if you prioritize responding to and investigating gunfire incidents, and in the process, increase community engagement. Many law enforcement agencies are resource poor, but given the high social and economic cost of gun violence, what better use of those resources is there than prioritizing them towards de-normalizing and deterring gun violence through a more comprehensive and precise response.

Now let’s look at the potential outcomes. Although ShotSpotter’s primary value proposition is in deterring gun violence and not necessarily driving high numbers of arrests, it is interesting to note that across our three deployments, we see a minimum of 40 arrests and a minimum of 25 guns seized, with as many as 103 guns seized in the one city that had over 8,000 activations. Even better are the NIBIN/IBIS hits that top off at 403 for the most active of our three cities. This is where the prevention and deterrence strategy is critical. The more quickly you can investigate and determine who your shooters are the more targeted you can be in your law enforcement interventions before there is a homicide. Most significantly, and perhaps more difficult to measure, is the huge social and economic benefit of an underserved community seeing comprehensive; timely and precise responses to gunfire incidents that previously had little to no response (that is a separate blog post).

This data provides us an interesting way to start a conversation with cities that are interested in reducing gun violence through a more comprehensive response strategy, but which are concerned with the resources needed to be successful. The analysis shows that contrary to what many believe, not having enough manpower to respond to gun violence is exactly why those cities should be considering ShotSpotter. The data from our three cities reveals some of the possibilities and demonstrates measurable outcomes.

November 17, 2017
By: Author is Ralph Clark, President & CEO of ShotSpotter