ShotSpotter Technology: Beyond Wireless briefing

Community Safety, Cultural Affairs and Sport (WCPP)

09 May 2018
Chairperson: Ms M Wenger (DA)
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Meeting Summary

The Committee was briefed on the ShotSpotter device which was designed to locate accurately instances in which gunfire occurred by using acoustics and mathematical algorithms. It could detect around 90% of instances of gunfire in public. More than just a tool for the detection of gunfire, ShotSpotter could assist law enforcement to combat crime more effectively by mapping problematic areas and mapping the times at which gunfire occurred.

While Cape Town was the only city which had commercially contracted ShotSpotter, there had been pilot programmes in Helenvale, Port Elizabeth, and Westbury, Johannesburg. The aim of ShotSpotter was to allow law enforcement to arrive at crime scenes more quickly in order to improve the chance of collecting better evidence in a case. There were currently two cases in Cape Town which had led to the arrest of individuals involved in gunfire, using the ShotSpotter technology. In a broader sense, ShotSpotter aimed to de-normalise gun violence in communities to mitigate the traumatic effects that gunfire had on children, as well as innocent people hurt from gunfire. Since the vast majority of gunfire went unreported, ShotSpotter could be used to alert law enforcement in real time to shooting events.

Members of the Committee asked questions about privacy and if the ShotSpotter’s acoustic tools could record private conversations. Could it be used to map crime and utilise patterns of crime in other areas? A question was raised as to why a particularly problematic street in Manenberg, notorious for gunfire, had not seen a decrease in gunfire after the implementation of ShotSpotter.

Meeting report

The Chairperson welcomed Members of the Committee, Mr Ian Lester, Chief Executive Officer (CEO) of Beyond Wireless, Mr Ralph Clark, President and CEO: ShotSpotter -- joining in via Skype from the United States of America -- and Mr Gideon Morris, Head: Department of Community Safety. She said this was one of two meetings they would be having on ShotSpotter. In June there would be a site visit to the operations centre. The Chairperson handed over to Mr Lester.

ShotSpotter: Background and introduction

Mr Lester, CEO: Beyond Wireless, said it had been a pleasure working with the City of Cape Town on the implementation of ShotSpotter. He asked Mr Clark to provide a brief background and introduction. He said they usually proceeded with presentations as a conversation, and requested Members of the Committee engage with him as he goes went with the presentation.

Mr Clark, President and CEO: ShotSpotter, said that ShotSpotter was founded 20 years ago by Dr Bob Showen, who was a brilliant engineer and scientist. He had become concerned over a local gunfire issue in Redwood City in California. He had the idea of applying mathematical principles of acoustics to locate outdoor gunfire. He had founded ShotSpotter, which had now been deployed in 85 cities, most of them in the USA, but also in Cape Town. Their aim was to provide law enforcement and communities with the tools to de-normalise gun violence. Most instances of gun fire went unreported by residents. ShotSpotter allowed law enforcement to collect evidence much better.   

The ShotSpotter used triangulation to pinpoint the location of gunfire. It employed acoustic specialists 24 hours a day to monitor gun fire. A video could be found on YouTube.

The Chairperson asked if the system could distinguish between different calibers of firearms.

Mr Lester said that the system could not determine caliber. It could only tell the difference between regular fire, semi-automatic fire, automatic fire or revolver fire. This was determined by the cadence of the sound. In Cape Town, ShotSpotter had detected only one instance of automatic fire during its early days. Automatic firearms were very rare.

Mr Clark said the system could also pick up multiple shooters involved, which could be crucial in preparing law enforcement for engagement.

Mr Lester said that on the Cape Flats, gunfights were seldom a one-sided affair. The ability to see the event play out was tactically important for responding law enforcement.

The Chairperson asked if ShotSpotter sensors could pick up peoples’ conversations with respect to privacy.

Mr Lester said that ShotSpotter did not use microphones. It used acoustic sensors programmed specifically to detect booms, pops and bangs. It recorded one second before the incident and one second after the incident. It was not constantly recording sound.

Ms T Dijana (ANC) asked where else in South Africa was ShotSpotter deployed. Would ShotSpotter be able to detect gunfire from guns which had silencers on?  

Mr Lester said that in Cape Town they had deployments in Manenberg and Hanover Park. They also had a pilot in Helenvale, Port Elizabeth, and in Westbury, Johannesburg. Cape Town was the only city that had commercially contracted ShotSpotter. They were looking to set up the ShotSpotter in Elderado Park.

On the issue of suppressed weapons, there were certain firearms that they could not detect. The quoted statistic indicated that ShotSpotter detected about 80% of gunfire that occurred, but in truth it was closer to 90%. Small caliber weapons could not be detected by ShotSpotter. A suppressed weapon could be problematic. There was also a problem if the shooter shot a victim at pointblank range, as the acoustic energy would be absorbed by the victim. If a shooter shot from inside a vehicle, it could also be problematic since the acoustic energy was contained within the vehicle. ShotSpotter may not be able to detect gunfire in areas which were tight in space.

ShotSpotter had been deployed in South Africa for the first time in the Kruger National Park to detect rhino poaching. Even with suppressors on poaching firearms, they had been able to detect gunfire since the caliber of the firearms used was very high.

Suppressors were extremely difficult to come by and the weapon used needed to be gunsmithed in order to accommodate a suppressor. A suppressor typically added 30 cm on to a firearm, and that made it very difficult to conceal the weapon.

Mr Clark commented that the use of a suppressor made firearms very hot, so the shooter could not conceal the weapon close to the body.

ShotSpotter in the community

Mr Lester said that the vast majority of gunfire goes unreported. In affected communities, people become so desensitised to gunfire that they do not bother reporting the incident unless someone is wounded or killed. Nine times out 10, incidents of gunfire go unreported. The police then cannot respond and that creates the perception that the police do not care. Communities do not cooperate with law enforcement because of this perception, as well as a fear of retribution. ShotSpotter allows law enforcement to respond quicker and with much greater location accuracy.

Only a small percentage of gang communities were habitual trigger pullers, so by taking a few individuals off the street there could be an exponential effect ion the fight against gun violence.

A lack of intelligence was dangerous. Despatching police officers to a scene without all the available information puts the officers’ lives at risk. There was also a better chance at getting more reliable eyewitness accounts and crime scene evidence. In Cape Town, there were currently two incidents in which the ShotSpotter technology had led to the arrest and prosecution of suspects. ShotSpotter was part of the evidence pack that would be used in the prosecution. ShotSpotter would also be used as evidence in a case that had occurred in the Kruger National Park. Since there was no precedent, it was yet to be determined how it would play out in South African courts.

Mr Lester said that at a meeting with the Cape Town metro police yesterday, they had been told that in one week where ShotSpotter had 79 activations, the emergency number at Cape Town’s metro police had rung only twice.

Where there was gun violence in communities, businesses shut down and it had a negative impact on the economy. Children who were exposed to gun violence may be more likely to suffer from learning disabilities, a loss of empathy and other psychological problems. Gun violence in communities could prevent children from going to school and getting a proper education. Children were more likely to turn to gangsterism if they dropped out of school in affected communities.

ShotSpotter was about more than getting criminals off the street and stopping gun violence -- it was also about trying to transform societies after the long term. Gun violence becomes normalised within communities, and it becomes a perpetuating cycle.

Mr Clark said that in the USA, there have been a number of studies done which determined the neurological effect that trauma had on children, and the effect could actually be seen in the way the brain developed. In the USA, there have been efforts not only to combat gun violence but also to deal with the traumatic effects that gun violence had on children, as well as working with communities at ground level to find alternatives to violent lifestyles.

Mr Lester said that affected individuals often turned to drugs and alcohol as a coping mechanism.

Mr Lester proceeded to show a demonstration of how the ShotSpotter detects the location of gunfire using algorithms. Once the ShotSpotter sensors were switched on, acoustic specialists listen to the sound and determine if the sound was in fact gunfire.

The majority of shooting that occurred did not result in a victim. Yet every time a gun was fired, it had the potential to injure someone seriously, and often the person who was hit was not the intended victim but an innocent bystander. ShotSpotter had an accuracy of about a 30-foot radius.

Mr Lester presented some statistics from a project that they had run for three months. He was very cautious to claim that the ShotSpotter was a victor in combating gun violence. Reductions in gun violence were transient. What they could see was that there had been a reduction, and a single incident where the wrong person got shot by the wrong individual could set off a chain of events. They had analysed the location and times of incidents of gunfire for the first two months of the project, and law enforcement had responded accordingly. When law enforcement began responding accordingly and placing resources in affected areas, there had been a significant drop in the incidence of gun violence over multiple days. It showed that if one responded more often, with greater accuracy and in less time, one could suppress gun violence. ShotSpotter then became more than just a reactionary tool. By analysing incidents of gunfire, one could place resources in affected areas in advance to suppress gunfire. ShotSpotter also helped law enforcement to optimise their limited available resources by targeting time and location incidents.


The Chairperson asked if they had a relationship with the South African Police Service (SAPS).

Mr Lester said that the question would be better if it was posed to the Cape Town metro police, since they were the coordinators. What they had seen was that there had been greater participation from SAPS. More police officers were getting alerts and more of them had the app on their phones.

Mr D Mitchell (DA) asked if the technology could be used for crime mapping.

Mr Lester said he did know that the metro police had crime analysts who looked at a lot of information that he had shared today. It was difficult to identify patterns as being common in different areas. SAPS and the metro police would be in a better position to answer that question.

Ms Dijana asked if the courts were using ShotSpotter data as evidence.

Mr Lester said that there had been two incidents where ShotSpotter had led to the arrest of individuals involved in shootings. ShotSpotter in the USA provided a digital forensic report, which was a document where the data had been analysed by a subject matter expert. It was then certified and notarised by an attorney in the USA and shipped over to South Africa, and would be used as evidence in a prosecution. How it would actually play out in South African law remained to be seen.

Mr Clark said they had been quite successful in using ShotSpotter data as evidence in prosecutions in the USA. It had been accepted in courts in over 27 states as forensically sound data.

Mr F Christians (ACDP) asked why, if law enforcement had the information at hand, there was still one specific street in Manenberg which contributed consistently to most incidents of gunfire in the area.

Mr Lester said there had been a prolonged period of high levels of gunfire. It had then been contained well, and there had been a period of about six months with very little gunfire. In April, a senior gang member had been killed, which had set in motion a chain of shooting incidents. They needed to start putting CCTV cameras in these problematic areas where incidents of gunfire were particularly persistent. He also called for the information and data to be used to lobby for more resources at the hands of law enforcement in terms of personal and patrol vehicles.

Mr Morris, Head: Department of Community Safety, said they had had many of these conversations already in the newly established Anti-Gangsterism Priority Committee, which functioned under the auspices of the Provincial Intelligence and Operations Committee, chaired jointly by Colonel Aaron and General Jula. They had identified that the technology worked exceptionally well, and it needed more resources to be implemented in areas such as Nyanga. The biggest challenge currently was a lack of a formal agreement between the City of Cape Town and the police on how these matters would be responded to.

Mr Lester said aside from the statistics on murders and attempted murders, it was important to note that discharging a firearm in a built-up area was a criminal offence. That in itself was a case that called for accountability.  

Adoption of minutes and reports

Ms Dijana moved the adoption of the draft minutes of 15 March 2018. Mr Mitchell seconded, and the minutes were adopted.

Mr Christians moved the adoption of the draft Annual Committee Activity Report of 2017/2018. Ms Dijana seconded, and the report was adopted..

In the draft quarterly report for January/March of 2018, the minutes of the meeting of 15 March would now change to read “adopted,” because it had been in a draft format before. Ms Dijana moved to adopt the report with the change. Mr Mitchell seconded the adoption, and the report was adopted.

Ms Dijana moved the adoption of the draft minutes of 18 April. Mr Mitchell seconded, and the minutes were adopted.

In the draft Oversight Visit Report to the Parow SAPS, Mr Mitchell noted that on page two it should read “Sub-council Chair.” Ms Dijana moved to adopt the Report, and Mr Christians seconded. The report was adopted.

Committee programme

The Chairperson said there were two meetings scheduled for this month -- on 16 and 30 May -- which were presentations by the Department of Community Safety. The Department may not be ready with the information requested by the Committee on 16 May. If that was so, then the meeting would be postponed to 16 June. The Chairperson would inform the Committee on the arrangement of the meeting. The meeting on 30 May would proceed.

The Committee would visit the control centre on 13 June. Members of the Committee were to inform the Committee Secretary if they wished transport to be arranged.  

The meeting was adjourned.

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