Acoustic Gunshot Detection Tech - the good, the bad, & the ugly

by Mateja Mihinjac

I’ve recently come across a report titled “ShotSpotter and the Misfires of Gunshot Detection Technology” by the STOP Surveillance Technology Project.

The report is extremely critical of this Acoustic Gunshot Detection Technology (AGDT) suggesting it offers little operational value for the police and it can prove detrimental with serious ethical caveats.

How bad is this technology really? 

SHOTSPOTTER®

ShotSpotter Inc. has been on the market for 20 years and it is the leading AGDT on the market used by over 200 police jurisdictions worldwide, with at least 130 of those from the US. 

ShotSpotter prides itself with the slogan: “Right place, right time. Precision policing solutions that help save lives, solve cases and deter crime – making communities safer.”

AGDT technology starts with microphones mounted above
the city on buildings and other tall structures

ShotSpotter combines narrow AI with human experts to identify and locate gunshot events and their location in the neighbourhoods where it’s been installed. Its detection system comprises microphones placed on streetlights, buildings and utility poles, and audio software that compares the sounds with prior gunshot events in its database. The system triangulates the location of the sound that is further reviewed by a human sound analyst who alerts the police should they determine the sound actually derives from a gunshot. 

THE GOOD

Company reports, and some technology reviews, offer that it detects shootings that would go unreported, locates gunshots for quick police response, and improves the arrest rates of suspects. This all leads to preventing gun violence and enhanced neighbourhood safety.

THE BAD

The evidence suggests that many of the above claims can be disputed. For example, while quasi-experimental studies indicated over 80% accuracy in detection and triangulation, other studies show the AGDT works poorly in detecting gunshots and, instead, it suffers from what researchers call “false positives” (it gets it wrong). 

Chicago’s Office of Inspector General review found that only 9.1% of probable gunshot alerts out of 50,000 records over a 17-month period resulted in evidence of a gun-related offence.

While we sleep at night, it listens for gunshots from roof-mounted
listening devices - what could go wrong?

These studies conclude that AGDT may actually be ineffective and inaccurate and can thus waste police resources. None of that mentions the cost, (Chicago paid $33 million for 2 years of service).

As well, there are poor outcomes on firearm offence reduction and shooting victims’ medical outcomes two years following the installation. Thus, it did not lead to gun violence deterrence as anticipated.

Most alarming was whether ShotSpotter evidence should be used in court. The company has previously admitted to altering the records and reclassifying the sounds that were initially not detected and determined as gunshots but were later reclassified as such based on police reports. While this may be occasionally warranted, at other times it may lead to the misuse of data and misrepresentation of the evidence on the side of the law enforcement agencies.  

THE UGLY

AGDT can lead the local community to become disengaged and stop reporting gunshots because they believe the technology will handle that for them. In St Louis, for example, citizen-initiated reports of gunshots before the installation of ShotSpotter were 7 times more useful than AGDT and wasted less police time. Following the installation, citizen reports significantly decreased and decreased further when the system was expanded.  

AGDT is predominantly deployed in poorer and majority Black and Latinx neighbourhoods commonly identified as hotspots for shootings and violence. While there might be more shooting incidents in those neighbourhoods, this automatically means AGDT will detect more shooting incidents in those specific neighbourhoods rather than in other neighbourhoods where it is not deployed. This might perpetuate the problem of over-policing and racial bias in communities of colour. 

Evaluations of AGDT shows problems with "false positives"
- it turns out the city can be a noisy place

There is a similar problem with another narrow AI program called predictive policing where there are reports of racial discrimination and over-policing and the additional concern of “tech washing”.

Despite ShotSpotter’s claim that the sensors cannot record private conversations, there are increasing concerns of the microphones recording regular conversations and acting as a “massive eavesdropping device”.

In one case, such a private conversation in a public space was intercepted and admitted into evidence in a murder trial court case.

Currently, there appear to be no regulations that would prevent ShotSpotter from sharing stored audio recordings.

SafeGrowth works directly with community residents in collaboration with the police to plan their own safety strategies

SMARTER APPROACHES

After two decades, the results of AGDT implementation continue to show few positive effects. In fact, some results are detrimental to effective police work, police-community relationships and community safety.

The evidence suggests that police leaders should err on the side of caution and turn towards approaches for addressing gun-related violence that have a better track record.

One example: combining neighbourhood policing and problem-oriented policing to build police-community relationships, act proactively, and approach the problem at its core. 

Another that we obviously recommend is SafeGrowth. This blueprint for neighbourhood safety planning helps residents help themselves, in partnership with police and using the latest in crime prevention. SafeGrowth provides a platform to help address gun-related violence and other crime and safety problems. 

The documented success story in the New Orlean’s gun-violent neighbourhood of Hollygrove is only one example of how neighbours disrupted gun violence. 

Sometimes the most effective solutions are not technology, they are human-based and neighbourhood friendly. That, we believe, is a future we all want. 

Reducing Zone 2 crime - The power of art co-ops

Denver Art Society Co-op in the heart of Denver's Santa Fe arts district
- photo Denver Art Society

by Gregory Saville

In last week’s blog, Tarah discussed the crime theory called concentric zones, that she lives in what feels like a Zone 2 city (Hamilton, Canada),  and how that theory predicts why crime clusters in Zone 2 areas around the central city. 

The question is what can be done about it. Some believe a Zone 2 high crime neighborhood will always be a high crime neighborhood. Experienced practitioners in crime prevention and community development know that is nonsense.

First, we know that carefully planned redevelopment can transform a high-crime neighborhood back from the brink. The CDC movement (community development corporations) is the lighthouse for redevelopment, such as the work of Philadelphia’s HACE organization and the work of the redevelopment corporation, LISC. The book Comeback Cities shows us how that is done.

True, that usually involves multi-year investments, big money, and long-term development. But there are other ways. 

Art murals appearing near Denver Art Society

NEVER THE FECKLESS

What does an art gallery have to do with creating livable places and cutting crime? Why should people looking to create safe places really care about an art gallery? If that gallery is part of the co-operative movement, it is worth a closer look.

When the urban writer Jane Jacobs wrote about safe places in her landmark book “The Death and Life of Great American Cities” she was, above all, talking about the social life of streets and how, exactly, those streets actually work. She wrote: 

“It may be that we have become so feckless as a people that we no longer care how things do work, but only what kind of quick, easy outer impression they give.”

If you look carefully at how co-operatives work, you will see why we should care and support them.

Denver city has now begun expanded streetscaping for better walkability

DENVER ART SOCIETY

Today co-ops are everywhere. The Denver Art Society (DAS) is such a co-op. A dozen years old, it comprises over 100 artists and musicians who teach, perform and sell their own art in the arts district of Denver. DAS is the epicenter of the Denver Santa Fe arts district with music shows, art displays, and classes. After a decade of operation, it has spurred the creation of other interesting businesses and street artifacts. For example, the city has begun streetscaping Santa Fe and local murals and cultural centers line the street. 

Like most co-ops, DAS is run by volunteer members who conduct community outreach to the neighborhood and also to local schools. They teach inexpensive art and music classes for burgeoning creatives. They have helped the homeless find a roof or a place of refuge. They beautify alleyways with mural painting events. When you understand how they actually work, art gallery coops are not a quick fix. They take time and can be complicated, often convoluted, undertakings. But, work they do. 

Primetime Emmy Award nominee, Kevin Nealon, Saturday Night Live comedian, on the DAS stage speaking at a free session about his art 

I admit a personal bias toward the Denver Art Society since my band MOOSGH was born there, our recording studio is based at DAS. There is still some theft, homelessness, and a few other problems in the area. But there is no doubt, from what the DAS founders and former residents describe, that this neighborhood is a FAR better place today than a decade ago. Police crime stats show the DAS neighborhood has a crime rate four times lower than the nearby CBD or the adjacent Capitol Hill neighborhood. 

As Jane Jacobs taught us many years ago, when people love a place, they end up looking after it. Co-ops help nurture that process. DAS has been doing that for years.

Nearby cultural center across from DAS. Cultural activities can
transform Zone 2 neighborhoods

CO-OPS - TRANSFORMING ZONE 2 AREAS

I have witnessed the co-op open gallery idea transform other Zone 2 neighborhoods in other cities. When you know the mechanics of how a neighborhood actually works, you can see why local co-ops are great Third Places - the very thing that prevent Zone 2 high crime hotspots from emerging. They are the kind of place that downtown Denver needs more than ever. All self-respecting urban planners, urban politicians, and crime prevention practitioners must study, learn, and adopt Third Places in their plans. 

The co-operative movement began with Welshman Robert Own in the 1800s, a wealthy cotton manufacturer who believed in creating livable communities for his workers. He helped them create a co-operative store so workers could lift themselves out of poverty by growing their own food, making and selling their own clothes, and otherwise working together to better their lives. 

It’s time city planners, decision-makers and criminologists paid more attention to the co-op movement.

Living in zone 2 - a Steel City in transition

On the street in Hamilton, Ontario

by Tarah Hodgkinson  

When we came back to Canada, we wanted to live somewhere affordable and close to work. But we also wanted to live in a city. I love city life. The different cultures of each neighbourhood, the density, the people, and the food options!

So, we chose Hamilton. It met all of our criteria. And importantly, the people felt real. I had lived in beautiful, but gentrified, cities like Vancouver and Brisbane. They were clean, beautiful, and had great amenities, but also expensive and exclusive.

Hamilton felt different. There were people from all walks of life here. It felt genuine. But Hamilton is also a city in transition. When we think about areas in transition, many criminologists or sociologists will be reminded of crime theories of social disorganization and concentric zones.

URBAN CRIME THEORY

In the early 1900s, criminologists Robert Park and Ernest Burgess outlined 5 concentric zones that made up city life in Chicago. These went from a zone surrounding the central business district (zone 1) all the way to the commuter zone in the wealthy suburbs (zone 5). Some zones, they said, were more vulnerable to crime.

Zone 2 neighbourhoods are in transition

Zone 2 was the zone in transition. This zone surrounded the central business district, and usually housed new immigrants or the poor as they could not afford to live anywhere but right beside the factories. When they made enough money, they would transition out of the area. This meant that there was very little cohesion and informal control in this zone, and as a result, this zone had the most crime.

Looking around Hamilton, the entire city feels like zone 2. Now, of course, there are areas that are beautiful and thriving. But having spoken to people working across the city, we’ve learned that Hamilton has fallen on hard times. COVID hit hard. People lost jobs and businesses. Poverty and homelessness are obvious and rampant. Mental health issues are evident everywhere. People here are struggling.

Hamilton feels like a Zone 2 city

Hamilton, like many of its struggling working-class city counterparts, is a manufacturing city.  The waterfront is lined with factories and 60% of the manufacturing is steel. But major employers like Stelco, have gone belly-up. And like Detroit and other manufacturing communities, Hamilton was hit hard by these major job losses.

SIGNS OF CHANGE

But there are also signs of change. Hamilton has been labeled Toronto’s “Brooklyn,” as many Torontonians are leaving the big city for more affordable housing (though it is still inaccessible to most people in the city) and funky and alternative places that support local art, food, and people (see Ottawa Street).

If there is one thing we’ve learned from places like Brooklyn though, the people of Hamilton are going to have to be careful to maintain an affordable and connected community. While it might seem easier to wait for external money to make Hamilton a suburb of Toronto, doing so would spell trouble for the people who live here now. Housing needs to stay affordable. Social services need to be improved for those who are struggling. 

As we have learned from working with folks from zones in transition around the world, one of the first steps down that path is by empowering neighbourhoods through methodologies like SafeGrowth. Like other zones in transition, Hamilton residents will need to take action to not only improve their community but also keep the things that make it great.  We can’t wait to see what happens next. 

Defund the police? Absurd! Re-fund and reframe? Absolutely!

State Capitol Building, South Dakota. The Law Enforcement Training Academy is a national leader in police instructor certification in problem-based learning.
Photo Travel South Dakota

GUEST BLOG: Gerard Cleveland is a school and youth violence prevention expert and an attorney based in Australia. He is co-author of Swift Pursuit: A Career Survival Guide for the Federal Officer. He is a frequent contributor to this blog, most recently regarding policing and drones. 

PROBLEM-SOLVERS, NOT CALL RESPONDERS

No one serious about public safety would advocate for the abolishment of our police agencies. We need them in times of emergency, as well as to investigate and solve community crime and disorder problems. However, we do need to have a serious discussion about what we want our police agencies to focus on in the next few decades.

Greg Saville and I just finished teaching a two-week problem-solving class called Problem-Based Learning for Police Educators at the Law Enforcement Training Academy in South Dakota with a wonderful group of dedicated and talented police and public service participants. Much of the course focused on ‘what next’ and we had senior police and sheriff executives, graduates from our previous classes, visit to tell us that as our communities change, so too must our public service agencies.

During all our training courses, we challenge police and community leaders to answer some key questions they will face in the years ahead, two of which include the metaverse and artificial intelligence.

The theoretical and futuristic cyberspace called the "metaverse" poses powerful challenges to policing

THE METAVERSE

If you are serving in a public role – in any agency – what plans and training have you undertaken to deal with issues in the metaverse? As that virtual area of our lives grows and becomes part of our daily activities, what role will police need to take?  If you are not sure that you need to address this issue yet, consider how much catching up policing agencies had to do with the arrival of crime on the web – especially the dark web – only a few decades ago. We do not want to be in the same position of catching up with technology as the metaverse extends its reach into our daily lives.

As well, what does your team know about the enhanced capabilities of privately owned drones? Many of our class members had never considered that the new threat of crime may be delivered via mini drones to your neighbourhoods. Their experience with drones generally extended to using police drones to clear buildings or watch traffic patterns, but almost no planning had been done to deal with drones being used for nefarious purposes by criminals. Greg describes one of the high-crime hotspots where his team brought SafeGrowth programming but then learned that the neighbourhood gang used drones to monitor police patrols.

ARTIFICIAL INTELLIGENCE 

Finally, how does your agency plan to address the development and growth of Artificial Intelligence (AI)? While AI will provide positive support for us in so many ways in medicine, engineering, traffic control, predictive policing, and a multitude of other ways, how have you begun to prepare – as parts of Asia have, for AI attacks on our infrastructure, our computers and even the vehicles we drive and the machines we operate?  

If you find yourself scratching your head wondering, “what do I do next?” we have a suggestion. Firstly, form some small groups with your police and community members and investigate and discuss what you can expect in the next 10 years from the above developments. Secondly, and most importantly, train your people to be problem solvers and thinkers, not reactive, call responders.  

But that last sentence is much harder than it sounds. We’ve been trying to change police training for the past two decades with limited success. I suspect that unless we reframe and fund strategies to address future trends, our current model of warrior responder will suddenly be quite irrelevant except in limited circumstances in the late 2020s and beyond. 

Emonika - an outdated transport plan for a modern city

by Mateja Mihinjac

Public transportation hubs provide commuting assets to every city. That’s why it’s crucial that they are well thought-out and become well integrated into the city ecosystem. 

A key form of transport hub is the Transit-Oriented Development (TOD) - a new Smart Growth form of city planning used in many cities to improve the integration of central stations and connecting services, as well as to promote the connectivity of services to populated parts of cities.

I wrote about TODs in Vancouver and Greg wrote about the central corridor TOD in St Paul, Minnesota. The Slovenian capital city of Ljubljana could benefit greatly from these considerations to improve currently underwhelming public transportation options. 

I recently joined the Institute for Spatial Policies’ (IPOP) Jane’s Walk where the participants discussed the proposed redevelopment of the new central station and transportation hub in Ljubljana.

EMONIKA 

The beginnings of this project date back to 2002. In 2006, the first building plan was approved but followed several revisions the 2 public-private partnerships were dissolved in the process. The project was also put on hold due to historical archaeological findings dating back to Roman Ljubljana – Emona, and ensuing excavations on the site. 

Fast forward 20 years and in April this year, new plans were announced envisioning a mixed-use development with commercial and business facilities, large parking facilities, a hotel, and exclusive apartments. 

However, it appears as if the transportation hub is now of secondary importance to this project, which is also alluded to on the project’s website:

“…A modern development that will be a hub of activity. It offers retail and entertainment experiences, state-of-the-art workplaces, a welcoming hotel and long-stay apartments. It offers first-class connectivity together with modern, stylish, urban places to live. It’s the heart of the city where life happens. It’s Ljubljana’s urban forum.”

Unsurprisingly, the proposal was met with several criticisms. In one piece, Katarina Žakelj of the Coalition for Sustainable Transport Politics questioned whether the project is still focused on the central station or whether it is a fiasco in the city centre.

We held similar discussions during the recent Jane’s Walk that I attended.  I heard concerns about insufficient time given to public consultations, problems with a large number of planned parking surfaces, and a lack of greenery which could worsen the heat island effect. 

INVITING CARS?

The site envisions 1700 new parking places for motor vehicles, around 900 of these will be for visitors, and the remaining for business and office facilities. With the municipality’s intention of reducing car traffic and car dependency by 20% before 2027, this plan appears counterintuitive. One US report recognises that while there are numerous benefits of a transportation hub, we need to reduce reliance on cars and instead integrate those provisions with better public transportation services.

RETAIL & BUSINESS FOCUS

At the Jane’s Walk, one of the participants exclaimed “not another shopping mall!” Both the retail and business focus of the development at this prime location appear counter-intuitive. 

This new shopping venue might affect the existing retail in the city and independent shops thus leading to vacant storefronts. According to some sources, Slovenia has one of the highest square footage of retail space per capita in the EU. 

Additionally, as many have expressed the preference for working from home, future cities should be more focused on the provision of social infrastructure.

SURROUNDING INFRASTRUCTURE 

One point of contention concerns intermodality. For example, Ljubljana has no unified system under which one could use the same ticket for different modes of transport. The concept called ZMAJ proposes this much-needed change together with the development of Emonika. As well, realizing the UN-Habitat concept of a 15-minute city means that the plan needs micromobility and other flexible transportation options.

TODs AND SAFETY 

TODs are an integrative and sustainable way to build future cities, but Emonika needs to consider issues such as growing population, environmental, economic, and social sustainability, and futureproofing, not just commercial needs. Among the most important needs is the personal safety and security of the site. 

To my knowledge, these topics have not yet been explicitly discussed on any of the forums I was able to source. The developers should not neglect the potential CPTED-related topics such as after-hours safety and social activity at micro-locations. 

After 20 years of waiting the residents of Ljubljana deserve a transportation hub fit for purpose.

Social amnesia in CPTED? For goodness sakes, read the science!

With the 1996 formation of the International CPTED Association, and the newly
formed ICA Canadian chapter, CPTED is now a global phenomenon

by Gregory Saville

Happy birthday to Canada (July 1) and to the USA (July 4). Why mention this? Because the US, and to a lesser extent Canada, are the birthplace countries of CPTED – Crime Prevention Through Environmental Design.

Some say CPTED began with my old friend Professor C. Ray Jeffery’s 1971 CPTED book. Some credit Canadian-born architect Oscar Newman’s 1972 book on American architecture - Defensible Space. But CPTED truly began with American/Canadian journalist Jane Jacobs’ 1961 book about American planning – The Death and Life of Great American Cities. 

A decade after Jacobs’ book, CPTED began in Canada when it was presented at a University of Toronto criminology workshop in 1975. One criminologist at that event, Professor Gwyn Nettler, challenged CPTED to do the necessary scientific research to prove the theory. How, he asked, was it possible to do crime prevention with such poor quality social science of the 1970s? In other words, don’t just make stuff up. 

I first studied defensible space and CPTED at university in the late 1970s. Many years later I spoke to Lew Haines, director of the Westinghouse CPTED studies in the 1970s, and urban planner Richard Schneider who implemented CPTED planning in Hartford in the 1970s. Those were the first-ever tests of CPTED. They used a principle called “motive reinforcement” for community-building tactics. They did not describe target hardening as a CPTED principle. 

Target hardening, a legitimate tactic in technical security,
was never intended as a CPTED strategy

Eventually, traditional CPTED removed the social aspects of motive reinforcement from the theory. Traditional CPTED now includes target hardening, a concept Jeffery and Jacobs could not care one whit about.

In CPTED books of the 1990s, traditional CPTED bore little resemblance to what Jeffery was recommending at the beginning. The truth is so-called traditional CPTED is nothing like the social ecology and interdisciplinary model in Jeffery’s writing. THAT was his point at a keynote address at the 1998 ICA CPTED conference in Mississauga, Canada. 

Both social and human ecology have a long tradition in the social sciences
- Jeffery mentioned them in his theories

How can we know the difference in CPTED between fluff and the right stuff? Based on Nettler’s principles, and as Carl Sagan once said, here are some basic theory-building steps: 

• go to the research; 
• check the logic; and 
• read original scientific publications.

Attempts to rewrite CPTED theory did not use these principles and ended up with ‘crime opportunity’ (aka, target hardening). Check the logic. Traditional CPTED – aka 1st Generation CPTED – became devoid of social factors. The largest bibliography on CPTED lists over 700 studies. For goodness sake, read at least some of the publications. 

A C. RAY JEFFERY MOMENT

That brings me to a recent blog of Tom McKay, a CPTED leader from Ontario. Tom is a former Peel Regional Police constable and he did CPTED duties after I retired from Peel Police having done the same thing. Tom is truly an exceptional fellow and went on to co-found CPTED Ontario. He was one of the original board members of the International CPTED Association. I have great respect for Tom McKay and his passion for CPTED.

Thus, it was with great disappointment I read a recent blog by him suggesting that both 2nd and 3rd Generation CPTED “run the real danger of confusing the utility of traditional concepts… and trivializing and or burying traditional concepts in an increasingly unwieldy model that bears little resemblance to the traditional CPTED flowchart”. 

Huh? 

Traditional CPTED, as it is now understood, was never promoted by C. Ray Jeffery. None of Jeffery’s ideas made it into the 1990s, only Newman’s. As criminologists Mateja Mihinjac and Danielle Reynald point out in a 2017 study, “contemporary CPTED is, owing to its practical  applicability, largely based upon Newman’s original conceptualization.”

That is what Jeffery was getting at. 

Originally intended for residential and mixed residential neighborhoods, today CPTED shows up in a wide range of urban environments such as parking lots

Tom recounts the opening address of C. Ray Jeffery at the Mississauga ICA CPTED conference. I was the one who brought Jeffery to that conference and published his remarks in the ICA Newsletter. I was teaching at Florida State University’s school of criminology and Professor Jeffery’s office was nearby. He was my colleague, my mentor, and my friend. I know his dictum that CPTED should “study crime in terms of the science of ecology and call for interdisciplinary research”. Jeffery’s point was that Newman’s defensible space (aka “traditional CPTED principles”) was the problem. 

In fact, 2nd and 3rd Generation CPTED were created to better align CPTED with the actual theory described by Jeffery. They are enhancements to the original theory and they are expansive and interdisciplinary – precisely what Jeffery was demanding. 

THE SECOND-GENERATION ANTIDOTE 

Second Generation CPTED has been around for two decades and has numerous scientific research studies published by members of the International CPTED Association.

Second Generation CPTED is neither new nor unproven. In fact it is now formally incorporated into the new ISO (International Standards Organization) CPTED standard, published worldwide last month, in part developed by members of the International CPTED Association. There is also the upcoming School CPTED Guidebook published by the ICA. It is the first formal document describing steps toward 1st, 2nd and 3rd Generation CPTED to prevent violence in schools. 

The ICA is about to publish another CPTED guidebook, this one on School Safety - the first ever to incorporate 1st, 2nd and 3rd Generation CPTED

You do not automatically do 2nd Generation CPTED if you teach 1st Generation CPTED “correctly” – an absurd idea I recently heard from a confused practitioner applying for CPTED certification. That is not how it works.

Second Generation CPTED builds on decades of research demonstrating some very precise principles such as social cohesion, community culture, and neighborhood capacity issues like blighted housing.

Tom cites an article by Sally Merry in her attempt to categorize early CPTED. Ironically, Merry bases her ideas partly on British criminologist R. Mawby. Unfortunately, Mawby makes the opposite conclusion to Merry. He criticized Defensible Space for its lack of attention to factors such as social class and income. In other words, traditional CPTED of that time, as now, was silent on the social ecology of a neighborhood. That is the point Jeffery made in Mississauga.

CPTED in this “traditional” form is NOT about the social fabric in a community. If social programs are intentionally incorporated into this form of CPTED training, they are done so in spite of this early writing, not because of it. 

With a few notable exceptions, social factors were washed out of early CPTED before the 1990s. In the so-called traditional CPTED, social fabric of crime is subsumed into fun-to-add artifacts of a CPTED program (neighborhood watch to enhance natural surveillance is not 2nd Generation CPTED). That is not the social ecology described by Jeffery.

SOCIAL AMNESIA IN TRADITIONAL CPTED

Jacobs was about healthy neighborhoods – places where people had plenty of pro-social behaviors and fewer exposures to crime. She described the crime prevention power of such activities as “tree planting, traffic calming, and community events.”

Newman realized his mistake in describing Defensible Space in physical terms that downplayed social factors. He restated his theory in his 1980 book “Community of Interest”. 

Newman's 1980 attempt to redefine defensible space in Community of Interest

But by then the traditional CPTED die was cast. CPTED courses far and wide taught territorial and access controls, natural surveillance, target hardening, landscaping, lighting, and so on. Go and research CPTED lesson plans on Google (basic or “advanced”… no matter). See for yourself. 

As for 2nd Generation CPTED, that has been taught for over a decade. We’ve taught it to residents, police officers, urban designers, community groups, and many others – like those in a New Orleans high-crime neighborhood – and they love it. They do not find these models confusing or unwieldy. They find them logical, and scientific, and they get positive results. They use 1st Generation CPTED, but they no longer stop with physical modifications. They build the capacity of their neighborhood so they have some say in their own safety. We argue this is the kind of CPTED that addresses Jeffery’s true concepts. 

In the free marketplace of ideas, all are welcome. Let scientific methods, logic, and original research guide the way.

The creation, modification, and expansion of theory happens through
scientific examination, checking the logic and building on prior research 

THE THIRD-GENERATION BREAKTHROUGH

A few years ago Mateja Mihinjac and I launched the most Jefferyesque version of CPTED since Mississauga – 3rd Generation CPTED. We spent years carefully examining the original CPTED theory. Mateja is completing her doctorate in CPTED and I have published prevention theories and studies for 35 years. We were careful to follow theory-building principles, and, true to Nettler and Sagan, our propositions and hypotheses aligned with the logic of theory-building and recent supporting research. We did not just make it up.

Third Generation CPTED is the newest kid on the theoretical CPTED block. Its scientific development is still underway. But make no mistake - there is already a significant body of evidence supporting 3rd Generation CPTED. It represents an exciting way to help our 21st Century city residents figure out how to build more inclusive, ethical, and sustainable communities as we grow into the future.

That is the Jeffery moment I am having.