Echoes of Everett Rogers’ Diffusion of Innovations: ShotSpotter Comes to the City of Cincinnati

Doug Collins - Wednesday, February 21, 2018

Have you heard of ShotSpotter?

The ShotSpotter company sets up microphones on the top of buildings within a community to capture sounds. The ShotSpotter software tied to the microphones can tell the difference between a gunshot and similar noises, such as the backfiring of a car. When the ShotSpotter software detects a gunshot, the system dials 911 to call the police. The police treat calls from the ShotSpotter system with the same urgency as they do call from citizens.

The City of Cincinnati, where I live, recently installed ShotSpotter in one of the neighborhoods, Avondale. Avondale has its share of wealth and poverty: well-maintained mansions built by beer barons and river traders, juxtaposed next to multi-tenant housing and empty lots.

From August to December 2017, the residents of Avondale called 911 forty (40) times to report gunshots. The newly installed ShotSpotter system reported two-hundred fifty-seven (257) gunshots during that time—six (6) times as many reported by residents.

In December 2017 the City of Cincinnati police surveyed Avondale residents. Fifty (50) percent said that “gunfire is my top concern.” By comparison, ten (10) percent of Avondale residents agreed with the statement that, “the police share my concern.”

When the police respond to a call about gunfire, they attempt to determine from where, exactly, the shots were fired. The City of Cincinnati police report that sixty (60) percent of the people involved in shootings leave the scene, either to escape the other party or to seek medical care. Many refuse to cooperate with the police in identifying the location of the shooting.

With the ShotSpotter system, the police have more success locating the scene of the shooting. With the location, they can more readily find the shell casings. The U.S. federal government manages the National Integrated Ballistic Information Network (NIBIN). The NIBIN provides a system by which the police can match casings from shells fired from the same gun.

Two of the early findings from the city’s experiment with ShotSpotter are that…

(1)    The gunfire is not as random and one-off as once thought. With the whole set of events in hand, the police have identified new clusters in the community where more gunfire tends to happen.

(2)    Some of the gunfire is clustered not only by location but also tied to a specific set of weapons. The police have more shell casings to test with the NIBIN to make this determination.

Diffusion of Innovations

The introduction of the ShotSpotter technology to the Avondale community holds promise—or would seem to hold promise. As I think about the unfolding story, I am reminded of Everett Rogers’ book, Diffusion of Innovations.

Rogers spent his career working with earlier adopter communities. Through his work he identified five (5) characteristics of innovations that could help to predict which would take root, or diffuse. The characteristics are as follows:

Relative advantage: the innovation offers a significant advantage over the current approach.

Compatibility: the innovation is perceived as being consistent with existing cultural values, accepted thinking, and perceived needs.

Complexity: the innovation requires minimal learning on behalf of users to implement.

Trialability: the innovation is easy—requires minimal upfront commitment—to try or test

Observability: the benefits from trying the innovation would be highly visible.

Of the above five, Rogers found that the first, relative advantage, was the most important predictor.

It’s intriguing to consider the question of relative advantage in the ShotSpotter example. What is the nature of the relative advantage? Who benefits from the relative advantage?

The police would seem to benefit. They enjoy a fuller, clearer view of gun violence in the community. They can make connections between seemingly isolated instances, either by geography or through matching an increased number of shell casings. They can find, for example, whether Pareto optimality exists: Are a handful of people—or weapons—responsible for most of the shootings?

The residents would seem to benefit. The ShotSpotter system validates the lack of safety that they feel in their community, given the high, actual number of gunshots. They have every reason to feel unsafe.

Have more arrests been made, however? Has the rate of gunfire decreased? The city states that it is too early to tell. They do not know. Cities that adopted ShotSpotter before Cincinnati report the same ambiguity. That is, they perceive the benefit of seeing the whole. However, they have not proved causation between having the big picture and increasing safety.

Disciples of Rogers will wonder whether the ambiguity around relative advantage might keep other cities from moving forward. As I understand, this topic has generated a lot of debate across police departments in the U.S.

In terms of compatibility, we find here, too, ambiguity. The City of Cincinnati pays the ShotSpotter company $200,000 per year to maintain the system for the community of Avondale. Extending the system to the rest of the city, which some city council members would like to do, would cost $2 million per year. In interviews with the local newspaper, the Enquirer, some residents of Avondale question whether that money might better be spent addressing the root causes of the gunfire.

Why are people shooting at one another in the first place? How might we eliminate those reasons?

Compatibility raises interesting questions from the perspective of the police. On the one hand, the police have better insight into the true scope of the problem. That benefit would seem to fall under the heading of general goodness or progress. On the other hand, the ShotSpotter system calls attention to the fact that the police were, in fact, missing eighty percent (80%) of the gunfire incidents in the community. Previously, the police asserted that they responded with urgency to all the 911 calls.

Fair enough. However, do 911 calls alone suffice as a proxy for understanding what is happening in the community?

And, now that the community as a whole now sees the entirety of the problem, what is the commitment for raising funds for the police to respond to six (6) times the number of calls? Is it, per Rogers, within the cultural values of the municipal leaders to pay the price to extend ShotSpotter to the rest of the city—and increase funding for the police, once the true scope of the problem is known?

Complexity appears to be manageable. The system is working as designed. The police are able to handle the increased number of service calls.

Two of Rogers’ attributes that would seem to help the ShotSpotter company diffuse its innovation to other cities is trialability and observability.

The municipal clients can try the system in one community, as the City of Cincinnati has done with Avondale. They can pay $200,000 to start, not $2 million. The trial has generated support among the police, some of the community, and apparently all the city leadership, thus paving the way for further adoption.

Observability would seem to play to the company’s advantage, too. People—the police, residents, and people who read the Enquirer—can see the scope of the problem that ShotSpotter has identified using maps and associated data modeling. Stakeholders can literally observe the larger pile of shell casings collected as evidence.

There is some ambiguity about how best to address the problem. There is seemingly no ambiguity that a problem exists and that it’s larger—six times larger—than the community appreciated, although the residents had been suffering at that level for years.

What’s Next

Last year an innovation in policing was introduced to one community in the City of Cincinnati.

What’s next?

In Cincinnati, the council will debate the pros and cons of paying to maintain the ShotSpotter system in Avondale, along with the timing to potentially expand the installation to other parts of the city where residents suffer from routinely high amounts of gunfire.

The City of Cincinnati police appear to be attuned to Rogers’ guidance to understand and then to articulate relative advantage. They are in heavy duty data collection mode.

What is the nature of relative advantage?

Does the ShotSpotter system, as part of the overall approach to policing, decrease the amount of gunfire?

Does the ShotSpotter system, as part of the overall approach to policing, increase the amount of safety that residents perceive?

Does the ShotSpotter system, as part of the overall approach to policing, increase the community’s level of understanding of why the gunfire exists in the first place?

Time will tell. In the meanwhile, fans of Rogers will find it interesting that other cities in the U.S. are deciding whether or not they, too, want to become early adopters of this technology that seems to have the potential of improving the effectiveness of policing in the community and perhaps, by extension, the relationships that the police enjoy with community residents.


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