̽��ֱ�� of Cambridge - Barak Ariel

Police platform patrols create ‘phantom effect’ that cuts crime in Tube stations

fpjl2 — Thu, 16 Jan 2020 15:02:29 +0000

A massive experiment that deployed regular police patrols on platforms has shown that four 15-minute patrols a day in some of the capital’s most crime-ridden Underground platforms reduced reported crime by 28% in patrolled locations, while it rose 16% on platforms without patrols.

Researchers from Cambridge ̽��ֱ��’s Institute of Criminology worked with the British Transport Police (BTP) to conduct the experiment across six months in 2011-2012. ̽��ֱ��findings have been published in the journal Criminology.

̽��ֱ��team identified the 115 London platforms where reported crime was highest. They randomly allocated 57 of these platforms to four daily 'doses' of patrols – two officers on foot for quarter of an hour – four days a week, and compared the effects to the remaining 'untreated' platforms.

Patrolled platforms dropped from 88 crimes in the preceding six months to 63 crimes on the same platforms during the six months of the experiment. In the same time periods, crimes on platforms without regular patrols increased from 64 to 74.

A total of 3,549 calls to police from the platform came from stations without patrols, compared to 2,817 in the stations receiving a policing 'dosage' – a relative difference of 21%.

Researchers also found that patrols on platforms did not simply 'displace' the crimes. Instead, the overall pattern showed crime going down in all parts of the stations – not just on platforms – relative to 'control' stations.

Strikingly, they discovered that the vast majority of reduction in both crime and calls for assistance occurred when these police patrols were absent – some 97% of the measured effect. ̽��ֱ��criminologists have dubbed this the “London Underground paradox”.

“ ̽��ֱ��total crime prevention benefit of police patrols may be greater when they are absent than when they are present,” said study co-author Prof Lawrence Sherman. “In the London Underground experiment we see a huge residual effect of brief appearances by patrolling officers after they leave”

“This phantom effect suggests that crime declines when potential offenders are apprehensive about a possible police presence based on recent patrolling patterns – even when there are no police in the vicinity,” he said.

“In London stations, it may be that more professional kinds of offenders are particularly sensitive to changes in police presence, such as pickpockets and distraction thieves.”

“ ̽��ֱ��London Underground paradox could have implications for debates on police priorities in an age of austerity, such as the benefits of investigating past crimes compared with the benefits of preventing future crimes,” Sherman said.

London’s Underground opened in 1863, the first underground railway in the world, and provides more than 1.3 billion passenger rides per year.

̽��ֱ��majority of crime in the transport network occurs on the trains and in concourse areas. Crime on platforms constitute 11% of the total, and historically platforms have had no regular police patrols.

As such, platforms offered an opportunity to conduct an experiment on spaces within a major metropolis that had never seen proactive police presence – ideal for gauging patrol effectiveness without previous 'contamination', say researchers.

“Platforms are small, stable and confined places with finite entry and exit points. These characteristics make them optimal for measuring the localised deterrence effects of police patrols,” said first author Dr Barak Ariel.

“We wanted to measure what happens when police patrols are introduced into an urban environment for the first time in over 150 years.”

̽��ֱ��team targeted 'hot spots' – areas where crime is more concentrated, and preventative patrols can have greatest effect – by ranking stations based on the previous year’s crime rates, and including the top 115 of Greater London’s 270 stations in the experiment.

Researchers also narrowed the experiment’s focus based on 'hot hours' and 'hot days'. Previous data showed the sample platforms experienced more crime and calls to police from Wednesday to Saturday between 3pm and 10pm.

Twenty uniformed BTP officers were selected and trained to work exclusively on patrolling the platforms of the 'treatment' stations during 'hot' days and hours. Each two-person unit was allocated between three and five stations, with platforms patrolled for 15 minutes four times a day.

Officers were asked to conduct these patrols in a random or unpredictable order within the 'hot hours', and encouraged to engage with the public while patrolling.

Police were most effective at preventing platform crime during periods and days when patrols were scheduled – but just 3% of that reduction came when officers were actually scheduled to patrol.

̽��ֱ��researchers also found 'regional' effects: crime in the rest of the station fell almost as much as crime on platforms during the four days when regular patrols were deployed.

“Our findings indicate that consistent patrols can cause large reductions in both crime and emergency calls in areas that have never before been proactively patrolled by police in this way,” added Sherman.

“ ̽��ֱ��more that uniformed police have been there, and the more recently, the less likely future crimes may be to occur.”

This story was amended on 17/01/20 to include additional details from the paper on reductions in crime.

A major experiment introducing proactive policing to Underground platforms finds that short bursts of patrolling create a 'phantom effect': 97% of the resulting crime reduction was during periods when police weren’t actually present.

̽��ֱ��London Underground paradox could have implications for debates on police priorities in an age of austerity

Lawrence Sherman

Marco Chilese

London Tube station

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Carrying Tasers increases police use of force, study finds

fpjl2 — Thu, 20 Dec 2018 00:01:49 +0000

A new study has found that London police officers visibly armed with electroshock ‘Taser’ weapons used force 48% more often, and were more likely to be assaulted, than those on unarmed shifts.

However, while use of force can include everything from restraint and handcuffing to CS spray, the Tasers themselves were only fired twice during the year-long study period.

Criminologists from the ̽��ֱ�� of Cambridge say the findings suggest that Tasers can trigger the ‘weapons effect’: a psychological phenomenon in which sight of a weapon increases aggressive behaviour.

While the ‘weapons effect’ has been repeatedly demonstrated in simulated conditions over the last forty years, this is one of the largest studies to show it “in the field” and the first to reveal the effect in law enforcement.

Researchers say their findings, published today in the journal Criminal Justice and Behaviour, may well apply to policing situations in which other forms of weaponry – including the lethal variety – are involved.

“We found that officers are more likely to be assaulted when carrying electroshock weaponry, and more likely to apply force,” said lead researcher Dr Barak Ariel from Cambridge’s Institute of Criminology.

“It is well established that the visual cue of a weapon can stimulate aggression. While our research does not pierce the ‘black box’ of decision-making, the only difference between our two study conditions was the presence of a Taser device.”

“There was no increase in injury of suspects or complaints, suggesting it was not the police instigating hostilities. ̽��ֱ��presence of Tasers appears to provoke a pattern where suspects become more aggressive toward officers, who in turn respond more forcefully,” he said.

̽��ֱ��City of London force is responsible for policing the ‘Square Mile’ business district in the centre of London. It also holds national responsibility for economic crime and prioritises counter-terrorism, violent crime and public order due to its central location.

̽��ֱ��force was the first in England and Wales to test “extended deployment” of Tasers – described as “conducted energy devices” in UK policing – to frontline officers. During the rollout, police chiefs allowed Ariel and colleagues to conduct a major experiment.

Between June 2016 and June 2017 the researchers randomly allocated 400 frontline shifts a Taser-carrying officer and compared the results to an equal number of unarmed shifts over the same period. A total of 5,981 incidents occurred during the study.

Use of force by police carrying Tasers was 48% higher than the officers on unarmed shifts. In what researchers call a “contagion effect”, even those unarmed officers accompanying Taser carriers on ‘treatment’ shifts used force 19% more often than those on Taser-free ‘control’ shifts.

Six physical assaults against police were recorded during shifts with Taser-carrying officers, compared to just three on the unarmed ‘control’ shifts. While the numbers are small, assaults against officers are rare, and researchers argue that this doubling is significant.

Despite the increased hostility uncovered by the study, actual use of electroshock weapons was minimal over the study period, with just nine “deholsterings” – only two of which resulted in electric shocks applied to a suspect.

“ ̽��ֱ��City of London police rarely discharged Tasers during the study. Yet the very presence of the weapon led to increased hostility between the police and public,” said Ariel.

̽��ֱ��weapons effect was first shown by psychologist Leonard Berkowitz in 1967, in a laboratory experiment involving the administering of electric shocks in the presence of a rifle – an experiment that Ariel points out has been replicated 78 times.

“For many, a weapon is a deterrence. However, some individuals interpret the sight of a weapon as an aggressive cue – a threat that creates a hostile environment,” Ariel said.

“ ̽��ֱ��response is consequently a ‘fight or flight’ dilemma that can result in a behavioural manifestation of aggression and assault. This is what we think we are seeing in our Taser experiment.”

“It would not be surprising to find that serious or violent offenders fit this criteria, especially young males – the very type of suspect that is regularly in direct contact with frontline police.”

Half a million police officers in the United States regularly carry Tasers, and electroshock weapons are now becoming part of frontline policing across the UK.

̽��ֱ��study author’s offer a simple solution to bypass the weapons effect: conceal the Tasers. “ ̽��ֱ��relatively inexpensive policy change of keeping Tasers hidden from sight should not limit efficacy, but could reduce the weapons effect we see in the study,” said Ariel.

“This conclusion could be generalised to all types of police armoury, including the lethal firearms carried by police officers. If the presence of weapons can lead to aggression by suspects, so its concealment should be able to reduce aggression and increase officer safety,” he said.

Study co-author Chief Superintendent David Lawes, from the City of London Police, said: “Following the findings of the study, we are exploring whether a simple holster change or weapon position move will nullify the weapons effect issue shown in the experiment. We have also updated our training package for officers carrying Tasers to make them aware of the findings.”

“ ̽��ֱ��use of Tasers have been a proportionate and sensible introduction to policing against a backdrop of unsophisticated terror attacks and an increase in violent crime across London.

“ ̽��ֱ��City of London Police seeks to ensure that any major changes to policy are supported by an evidence base and we wanted to be confident that an extension of Taser deployments to our frontline responders was the right thing to do for both our officers and the public they serve.

“A number of other forces are interested in replicating the study to add to the evidence base and see whether the experiment produces the same results outside of London.

“Across our force, we will continue to use evidence to define how we target problems, which tactics we should use and how we can ensure policing is efficient and safer for both the general public and our officers.”

Cambridge experiment with City of London police found that, while rarely deployed, just the presence of electroshock devices led to greater overall hostility in police-public interactions – an example of what researchers call the ‘weapons effect’.

̽��ֱ��presence of Tasers appears to provoke a pattern where suspects become more aggressive toward officers, who in turn respond more forcefully

Barak Ariel

City of London Police

A City of London police officer armed with a Taser

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Vice-Chancellor’s awards recognise the difference researchers make to society

cjb250 — Thu, 13 Jul 2017 10:44:35 +0000

̽��ֱ��announcement was made at a prize ceremony held at the Old Schools on 13 July. At the same event, one of Cambridge’s leading experts on EU law – and in particular, Brexit – received one of the Vice Chancellor’s Public Engagement with Research Awards for her work around the EU Referendum.

Professor Sir Leszek Borysiewicz, Vice-Chancellor of the ̽��ֱ�� of Cambridge, says: “I would like to offer my warm congratulations to the recipients of our Impact and Public Engagement Awards. These are outstanding examples that reflect the tremendous efforts by our researchers to make a major contribution to society.”

Vice-Chancellor’s Impact Awards

̽��ֱ��Vice-Chancellor’s Impact Awards were established to recognise and reward those whose research has led to excellent impact beyond academia, whether on the economy, society, culture, public policy or services, health, the environment or quality of life. Each winner receives a prize of £1,000 and a trophy, with the overall winner - Dr Alexander Patto from the Department of Physics – receiving £2,000.

This year’s winners are:

Overall winner: Dr Alexander Patto (Department of Physics)

WaterScope

Using an open-source flexure microscope, spin-out company WaterScope is developing rapid, automated water testing kits and affordable diagnostics to empower developing communities. Its microscopes are being used for education, to inspire future scientists from India to Colombia. Its open-source microscope is supporting local initiatives, with companies such as STIClab in Tanzania making medical microscopes from recycled plastic bottles.

Elroy Dimson (Judge Business School)

‘Active Ownership’: Engaging with investee companies on environmental and social issues

‘Active Ownership’ refers to commitment by asset owners and their portfolio managers to engage with the businesses they own, focusing on issues that matter to all stakeholders and to the economy as a whole, including environmental, social and governance (ESG) concerns. By providing evidence to guide ESG strategy, Professor Dimson’s research has had a substantial impact on investment policy and practice.

Professor Nick Morrell (Department of Medicine)

From genetics to new treatments in pulmonary arterial hypertension

Severe high blood pressure in the lungs, known as idiopathic pulmonary arterial hypertension, is a rare disease that affects approximately 1,000 people in the UK. ̽��ֱ��condition usually affects young women and average life expectancy is three to five years. Existing treatments improve symptoms but have little impact on survival. Professor Morrell has introduced routine genetic testing for this condition, and found that one in four patients carry a particular genetic mutation associated with more severe disease and worse survival. His research has identified new ways to treat the disease, the most promising of which is being commercialised through a university spin-out biotech company.

Professor Lawrence Sherman, Peter Neyroud, Dr Barak Ariel, Dr Cristobal Weinborn and Eleanor Neyroud (Institute of Criminology)

Cambridge Crime Harm Index

̽��ֱ��Cambridge Crime Harm Index is a tool for creating a single metric for the seriousness of crime associated with any one offender, victim, address, community, or prevention strategy, supplementing traditional measures giving all crimes equal weight. ̽��ֱ��UK Office of National Statistics credits the index as the stimulus to institute its own, modified version from 2017. Police use the Cambridge index to target highest-harm offenders, victims, places, times and days, differences in crime harm per capita differs across communities or within them over time, adding precision to decisions for allocating scarce resources in times of budget cuts.

Vice-Chancellor’s Public Engagement with Research Awards

̽��ֱ��Vice-Chancellor’s Public Engagement with Research Awards were set up to recognise and reward those who undertake quality engagement with research. Each winner receives a £1000 personal cash prize and a trophy. This year’s winners are:

Professor Catherine Barnard (Faculty of Law)

In the run up to the EU membership referendum Professor Barnard developed a range of outputs to explain key issues at stake including migration, which forms the basis of her research, in addition to the wider EU law remit. Harnessing the timeliness of the political climate, Barnard’s videos, online articles, radio and TV interviews have supported her engagement across 12 town hall events from Exeter to Newcastle, an open prison and round-table discussions with various public groups. She has also provided a number of briefing sessions to major political party MPs and peers. She has become a trusted public figure, and researcher, on EU law, Brexit and surrounding issues, ensuring that the voices of those key to the research process are heard and listened to.

Dr Elisa Laurenti (Wellcome/MRC Stem Cell Institute and Department of Haematology)

Dr Laurenti has engaged over 2,500 people, at six separate events, with her Stem Cell Robots activity. She collaborated with a researcher in educational robotics to produce this robot-based activity, which maps a stem cell’s differentiation to become a specific cell type. ̽��ֱ��activity has provided a platform for children, families and adults to discuss ethics and clinical applications of stem cell research.

Dr Nai-Chieh Liu (Department of Veterinary Medicine)

Dr Liu has developed a non-invasive respiratory function test for short-skulled dog breeds, including French bulldogs and pugs, which suffer from airway obstruction. She has engaged with dog owners by attending dog shows, dog club meetings and breeders’ premises to break down barriers between publics and veterinarians working to improve the health of these dogs. As a result of this engagement, the UK French bulldog club and the Bulldog Breed Council have adopted health testing schemes based on Dr Liu’s research.

Dr Neil Stott and Belinda Bell (Cambridge Centre for Social Innovation, Judge Business School)

Dr Stott and Miss Bell established Cambridge Social Ventures to embed research around social innovation into a practical workshop to support emerging social entrepreneurs. Since the first workshop in 2014, they have reached almost 500 people wanting to create social change by starting and growing a business. ̽��ֱ��team goes to considerable efforts to reach out to participants from non-traditional backgrounds and to ensure workshops are inclusive and accessible to a wide range of people by incorporating online engagement with work in the community.

Amalia Thomas (Department of Applied Mathematics and Theoretical Physics)

Amalia Thomas researches photoelasticity, a property by which certain materials transmit light differently when subjected to a force. Amalia has developed an engaging exhibition for secondary school students comprising interactive elements, which uses photoelasticity to visualise force, work and power.

Dr Frank Waldron-Lynch, Jane Kennet and Katerina Anselmiova (Department of Medicine and Department of Clinical Biochemistry)

Since the commencement of their research programme to develop drugs for Type 1 Diabetes, Dr Waldron-Lynch, Ms Kennet and Ms Anselmiova have developed a public engagement programme to engage participants, patients, families, funders, colleagues, institutions, companies and the community, with the aim of ensuring that their research remains relevant to stakeholder needs. Amongst their outputs, the team has formed a patient support group in addition to developing an online engagement strategy through social media platforms. Most recently, they have collaborated with GlaxoSmithKline to offer patients the opportunity to participate in clinical studies at all stages of their disease.

An open source, 3D-printable microscope that forms the cornerstone of rapid, automated water testing kits for use in low and middle-income countries, has helped a Cambridge researcher and his not-for-profit spin-out company win the top prize in this year’s Vice-Chancellor’s Impact Awards at the ̽��ֱ�� of Cambridge.

Nithi Anand

I drink because I'm thirsty

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Use of body-worn cameras sees complaints against police ‘virtually vanish’, study finds

fpjl2 — Thu, 29 Sep 2016 05:05:57 +0000

Body-worn cameras are fast becoming standard kit for frontline law enforcers, trumpeted by senior officers and even the US President as a technological ‘fix’ for what some see as a crisis of police legitimacy. Evidence of effectiveness has, however, been limited in its scope.

Now, new results from one of the largest randomised-controlled experiments in the history of criminal justice research, led by the ̽��ֱ�� of Cambridge’s Institute of Criminology, show that the use by officers of body-worn cameras is associated with a startling 93% reduction in citizen complaints against police.

Researchers say this may be down to wearable cameras modifying behaviour through an ‘observer effect’: the awareness that encounters are recorded improves both suspect demeanour and police procedural compliance. Essentially, the “digital witness” of the camera encourages cooler heads to prevail.

̽��ֱ��experiment took place across seven sites during 2014 and early 2015, including police from areas such as the UK Midlands and the Californian coast, and encompassing 1,429,868 officer hours across 4,264 shifts in jurisdictions that cover a total population of two million citizens. ̽��ֱ��findings are published today in the journal Criminal Justice and Behaviour.

̽��ֱ��researchers write that, if levels of complaints offer at least some guide to standards of police conduct – and misconduct – these findings suggest that use of body-worn cameras are a “profound sea change in modern policing”.

“Cooling down potentially volatile police-public interactions to the point where official grievances against the police have virtually vanished may well lead to the conclusion that the use of body-worn cameras represents a turning point in policing,” said Cambridge criminologist and lead author Dr Barak Ariel.

“There can be no doubt that body-worn cameras increase the transparency of frontline policing. Anything that has been recorded can be subsequently reviewed, scrutinised and submitted as evidence.”

“Individual officers become more accountable, and modify their behaviour accordingly, while the more disingenuous complaints from the public fall by the wayside once footage is likely to reveal them as frivolous.

“ ̽��ֱ��cameras create an equilibrium between the account of the officer and the account of the suspect about the same event – increasing accountability on both sides.”

However, Ariel cautions that one innovation, no matter how positive, is unlikely to provide a panacea for a deeply rooted issue such as police legitimacy.

Complaints against police are costly: both financially and in terms of public trust, say researchers. In the US, complaints can be hugely expense – not least through multimillion-dollar lawsuits. In the UK last year, the IPCC reported a continuous rise in complaints across the majority of forces.

Ariel worked with colleagues from RAND Europe and six different police forces: West Midlands, Cambridgeshire, West Yorkshire, the Police Service of Northern Ireland, and Rialto and Ventura in California, to conduct the vast experiment.

Each trial was managed by a local point of contact, either an officer or civilian staff member – all graduates of the Cambridge ̽��ֱ�� Police Executive Programme.

Every week for a year, the researchers randomly assigned each officer shift as either with cameras (treatment) or without (control), with all officers experiencing both conditions.

Across all seven trial sites during the 12 months preceding the study, a total of 1,539 complaints were lodged against police, amounting to 1.2 complaints per officer. By the end of the experiment, complaints had dropped to 113 for the year across all sites – just 0.08 complaints per officer – marking a total reduction of 93%.

Surprisingly, the difference between the treatment and control groups once the experiment began was not statistically significant; nor was the variations between the different sites.

Yet the before/after difference caused by the overall experimental conditions across all forces was enormous. While only around half the officers were wearing cameras at any one time, complaints against police right across all shifts in all participating forces almost disappeared.

Researchers say this may be an example of “contagious accountability”: with large scale behavioural change – in officers but also perhaps in the public – seeping into almost all interactions, even during camera-less control shifts, once the experiment had introduced camera protocols to participating forces.

“It may be that, by repeated exposure to the surveillance of the cameras, officers changed their reactive behaviour on the streets – changes that proved more effective and so stuck,” said co-author Dr Alex Sutherland of RAND Europe.

“With a complaints reduction of nearly 100% across the board, we find it difficult to consider alternatives to be honest,” he said.

Critically, researchers say these behaviour changes rely on cameras recording entire encounters, and officers issuing an early warning that the camera is on – reminding all parties that the ‘digital witness’ is in play right from the start, and triggering the observer effect.

In fact, results from the same experiment, published earlier this year, suggest that police use-of-force and assaults on officers actually increase if a camera is switched on in the middle of an interaction, as this can be taken as an escalation of the situation by both officer and suspect.

“ ̽��ֱ��jolt of issuing a verbal reminder of filming at the start of an encounter nudges everyone to think about their actions more consciously. This might mean that officers begin encounters with more awareness of rules of conduct, and members of the public are less inclined to respond aggressively,” explained Ariel.

“We suspect that this is the ‘treatment’ that body-worn cameras provide, and the mechanism behind the dramatic reduction in complaints against police we have observed in our research.”

Drs Barak Ariel and Alex Sutherland will be giving a public talk on this research and the future of policing at the Cambridge Festival of Ideas on Monday 17 October. Book a free place here: http://www.festivalofideas.cam.ac.uk/events/body-worn-cameras-safety-or-...

Year-long study of almost 2,000 officers across UK and US forces shows introduction of wearable cameras led to a 93% drop in complaints made against police by the public – suggesting the cameras result in behavioural changes that ‘cool down’ potentially volatile encounters.

There can be no doubt that body-worn cameras increase the transparency of frontline policing. Anything that has been recorded can be subsequently reviewed, scrutinised and submitted as evidence

Barak Ariel

Body-worn video - ̽��ֱ��independent witness

Image from a body-worn camera

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Policing: two officers ‘on the beat’ prevent 86 assaults and save thousands in prison costs

fpjl2 — Tue, 14 Jun 2016 15:05:10 +0000

New research shows that targeting each crime ‘hot spot’ in a city with 21 extra minutes of daily foot patrolling by Police Community Support Officers (PCSOs) could save the justice system hundreds of thousands of pounds through prevented crime.

Working with Cambridgeshire Constabulary to conduct a year-long experiment in Peterborough, researchers from the Institute of Criminology at the ̽��ֱ�� of Cambridge randomly allocated 34 crime-prone areas to get 21 minutes of extra PCSO patrols a day.

They compared offences before and after the experiment between 38 hot spots with no increased patrol and the 34 with the increase using the Cambridge Crime Harm Index: a new tool that measures “harm caused to victims” by modelling severities in sentencing for different offences, rather than just totting up overall crime figures.

̽��ֱ��research team calculated that targeted patrol time equal to two full-time PCSOs would prevent 86 assaults a year, or incidents of the equivalent crime ‘harm value’, saving potential costs to the public of eight years of imprisonment.

̽��ֱ��findings, published in the Journal of Experimental Criminology, suggest that every £10 spent on targeted foot patrols prevents a further £56 in prison costs – a five-to-one return on investment.

While modern policing is characterised by a “reactive, fire-brigade” approach, usually vehicle-based, the researchers say their evidence strengthens support for the historic “bobbies on the beat” mode of policing focused on crime-prone areas.

“By working with us to conduct this experiment, Cambridgeshire Constabulary has set the standard for cost-effectiveness in policing,” said study co-author Professor Lawrence Sherman, Director of the Cambridge Institute of Criminology and its Jerry Lee Centre for Experimental Criminology.

“Any other investment in policing can now be challenged to match the benefits of foot patrols in preventing the equivalent of either 86 assaults, or six burglaries, or six sexual crimes.”

‘Hot spots’ are small urban areas, streets or intersections, where there is a concentration of crime – usually offences such as theft, burglary, violence and criminal damage.

During the experiment, 72 of Peterborough’s ‘hottest’ hot spots randomly received either standard patrols (the control) or an average extra 21 minutes PCSO foot patrol per day (the treatment) over the course of a year.

In the ‘treated’ hot spots, these additional patrols – combined with vehicle patrols by Police Constables (PCs) these areas already received – amounted to an average increase of 56% in daily patrol time.

GPS devices embedded in the radios of both PCs and PCSOs were used to track time spent in each location, a precise measure of the “treatment dosage” of police presence.

̽��ֱ��researchers found that, on average per hot spot, 39% fewer crime incidents were reported by victims and 20% fewer 999 emergency calls to the police occurred in the 34 treated hot spots compared with the 38 control hot spots.

̽��ֱ��extra 21 minutes of PCSO time per day for each of the hot spots amounts to 3,094 hours across all treatment areas, roughly equivalent to two fulltime PCSOs – no more than £50,000 on current salaries.

̽��ֱ��Cambridge Crime Harm Index analysis suggests that, across all 34 treated hot spots, the equivalent of these two extra officers prevented crime amounting to 2,914 days – around eight years – of imprisonment, at a potential cost to the public of £280,000 under English sentencing guidelines.

“ ̽��ֱ��use of the Cambridge Crime Harm Index and the Peterborough cost-effectiveness results provides a like-for-like metric to challenge those who demand more PC or PCSO time in patrolling schools, low-crime neighbourhoods, or traffic accident hot spots,” Sherman said.

“This study should give both Police and Crime Commissioners and Chief Constables a benchmark for evaluating any other uses of police time other than hot spots patrols.”

PCSOs are civilian members of police staff, used to bolster police presence and support PCs. They have no power of arrest, and cannot investigate crimes, but have specific powers to deal with minor public order offices – what’s known as “soft policing”.

Budgetary constraints in British policing mean PCSOs are the only officers who now conduct proactive and visible foot patrols. During the experiment, the PCSOs were told to concentrate on being visible to the exclusion of any other task.

̽��ֱ��researchers’ experimental evidence showed that every additional PCSO visit per day to the treatment hot spots decreased calls for service by approximately 34, with the number of crimes declining by around four.

“ ̽��ֱ��experiment suggests that the number of visits to each hot spot may matter more than the total minutes – as if each time the police arrive they renew their deterrent effect on crime,” said Dr Barak Ariel of the Lee Centre of Experimental Criminology, who was lead researcher on the Peterborough experiment.

Sherman says the latest results show that, if deployed tactically and proactively, ‘soft’ policing can achieve comparable crime reductions to the ‘hard’ threat of immediate physical arrest.

“These findings suggest that the probability of encountering an officer is more important than the powers that officer has, and that the frequency and duration of proactive patrolling deserves far more attention,” said Sherman.

“More experiments like this one can produce an even more general estimate of the value of foot patrol activity, to make that value the ‘gold standard to beat’ in selecting cost-effective policing strategies,” he added.

Professor Lorraine Mazerolle of the ̽��ֱ�� of Queensland and Editor of the Journal of Experimental Criminology said the Peterborough experiment showed that “the deterrent role of police and PCSOs patrolling crime-harm hotspots is now indisputable: the police can, and do, prevent crime, they just need to be appropriately deployed to crime-harm hotspots.”

Cambridgeshire Constabulary’s Assistant Chief Constable Mark Hopkins said: “We’re pleased to have worked with the Cambridge Institute of Criminology to conduct this research and we welcome the outcomes.

“We’re keen to look at the findings in further detail and explore how they could help to influence our future policing plan.”

̽��ֱ��results of a major criminology experiment in Peterborough suggest that investing in proactive PCSO foot patrols targeting crime ‘hot spots’ could yield a more than five-to-one return: with every £10 spent saving £56 in prison costs.

̽��ֱ��use of the Cambridge Crime Harm Index and the Peterborough cost-effectiveness results provides a like-for-like metric to challenge those who demand more PC or PCSO time in patrolling schools, low-crime neighbourhoods, or traffic accident hot spots

Lawrence Sherman

West Midlands Police

PCSOs from West Midlands Police on patrol

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Body-worn cameras associated with increased assaults against police, and increase in use-of-force if officers choose when to activate cameras

fpjl2 — Tue, 17 May 2016 08:10:07 +0000

New evidence from the largest-yet series of experiments on use of body-worn cameras by police has revealed that rates of assault against police by members of the public actually increased when officers wore the cameras.

̽��ֱ��research also found that on average across all officer-hours studied, and contrary to current thinking, the rate of use-of-force by police on citizens was unchanged by the presence of body-worn cameras, but a deeper analysis of the data showed that this finding varied depending on whether or not officers chose when to turn cameras on.

If officers turned cameras on and off during their shift then use-of-force increased, whereas if they kept the cameras rolling for their whole shift, use-of-force decreased.

̽��ֱ��findings are released today across two articles published in the European Journal of Criminology and the Journal of Experimental Criminology.

While researchers describe these findings as unexpected, they also urge caution as the work is ongoing, and say these early results demand further scrutiny. However, gathering evidence for what works in policing is vital, they say.

“At present, there is a worldwide uncontrolled social experiment taking place – underpinned by feverish public debate and billions of dollars of government expenditure. Robust evidence is only just keeping pace with the adoption of new technology,” write criminologists from the ̽��ֱ�� of Cambridge and RAND Europe, who conducted the study.

For the latest findings, researchers worked with eight police forces across the UK and US – including West Midlands, Cambridgeshire and Northern Ireland’s PSNI, as well as Ventura, California and Rialto, California PDs in the United States – to conduct ten randomised-controlled trials.

Over the ten trials, the research team found that rates of assault against officers wearing cameras on their shift were an average of 15% higher, compared to shifts without cameras.

̽��ֱ��researchers say this could be due to officers feeling more able to report assaults once they are captured on camera – providing them the impetus and/or confidence to do so.

̽��ֱ��monitoring by camera also may make officers less assertive and more vulnerable to assault. However, they point out these are just possible explanations, and much more work is needed to unpick the reasons behind these surprising findings.

In the experimental design, the shift patterns of 2,122 participating officers across the forces were split at random between those allocated a camera and those without a camera. A total of 2.2 million officer-hours policing a total population of more than 2 million citizens were covered in the study.

̽��ֱ��researchers set out a protocol for officers allocated cameras during the trials: record all stages of every police-public interaction, and issue a warning of filming at the outset. However, many officers preferred to use their discretion, activating cameras depending on the situation.

Researchers found that during shifts with cameras in which officers stuck closer to the protocol, police use-of-force fell by 37% over camera-free shifts. During shifts in which officers tended to use their discretion, police use-of-force actually rose 71% over camera-free shifts.

“ ̽��ֱ��combination of the camera plus the early warning creates awareness that the encounter is being filmed, modifying the behaviour of all involved,” said principal investigator Barak Ariel from the ̽��ֱ�� of Cambridge’s Institute of Criminology.

“If an officer decides to announce mid-interaction they are beginning to film, for example, that could provoke a reaction that results in use-of-force,” Ariel said. “Our data suggests this could be what is driving the results.”

̽��ֱ��new results are the latest to come from the research team since their ground-breaking work reporting the first experimental evidence on body-worn cameras with Rialto PD in California – a study widely-cited as part of the rationale for huge investment in this policing technology.

“With so much at stake, these findings must continue to be scrutinised through further research and more studies. In the meantime, it’s clear that more training and engagement with police officers are required to ensure they are confident in the decisions they make while wearing cameras, and are safe in their job,” said co-author and RAND Europe researcher Alex Sutherland.

Ariel added, “It may be that in some places it’s a bad idea to use body-worn cameras, and the only way you can find that out is to keep doing these tests in different kinds of places. After all, what might work for a sheriff’s department in Iowa may not necessarily apply to the Tokyo PD.”

Preliminary results from eight UK and US police forces reveal rates of assault against officers are 15% higher when they use body-worn cameras. ̽��ֱ��latest findings, from one of the largest randomised-controlled trials in criminal justice research, highlight the need for cameras to be kept on and recording at all stages of police-public interaction – not just when an individual officer deems it necessary – if police use-of-force and assaults against police are to be reduced.

It may be that in some places it’s a bad idea to use body-worn cameras, and the only way you can find that out is to keep doing these tests in different kinds of places

Barak Ariel

Screenshot of footage from a police body-worn camera

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First scientific report shows police body-worn-cameras can prevent unacceptable use-of-force

fpjl2 — Tue, 23 Dec 2014 11:18:26 +0000

Researchers from the ̽��ֱ�� of Cambridge’s Institute of Criminology (IoC) have now published the first full scientific study of the landmark crime experiment they conducted on policing with body-worn-cameras in Rialto, California in 2012 — the results of which have been cited by police departments around the world as justification for rolling out this technology.

̽��ֱ��experiment showed that evidence capture is just one output of body-worn video, and the technology is perhaps most effective at actually preventing escalation during police-public interactions: whether that’s abusive behaviour towards police or unnecessary use-of-force by police.

̽��ֱ��researchers say the knowledge that events are being recorded creates “self-awareness” in all participants during police interactions. This is the critical component that turns body-worn video into a ‘preventative treatment’: causing individuals to modify their behaviour in response to an awareness of ‘third-party’ surveillance by cameras acting as a proxy for legal courts — as well as courts of public opinion — should unacceptable behaviour take place.

During the 12-month Rialto experiment, use-of-force by officers wearing cameras fell by 59% and reports against officers dropped by 87% against the previous year’s figures.

However, the research team caution that the Rialto experiment is only the first step on a long road of evidence-gathering, and that more needs to be known about the impact of body-worn cameras in policing before departments are “steamrolled” into adopting the technology — with vital questions remaining about how normalising the provision of digital video as evidence will affect prosecution expectations, as well as the storage technology and policies that will be required for the enormous amount of data captured.

President Obama recently promised to spend $263m of federal funds on body-worn-video to try and stem the haemorrhaging legitimacy of US police forces among communities across the United States after the killing of several unarmed black men by police caused nationwide anguish, igniting waves of protest.

But some in the US question the merit of camera technology given that the officer responsible for killing Eric Garner — a 43-year-old black man suffocated during arrest for selling untaxed cigarettes — was acquitted by a grand jury despite the fact that a bystander filmed the altercation on a mobile phone, with footage showing an illegal ‘chokehold’ administered on Garner who repeatedly states: “I can’t breathe”. (A medical examiner ruled the death a homicide).

For the Cambridge researchers, the Rialto results show that body-worn-cameras can mitigate the need for such evidence by preventing excessive use-of-force in the first place. Data from the Rialto experiment shows police officers are deterred from unacceptable uses-of-force — indeed, from using force in general — by the awareness that an interaction is being filmed; but this ‘deterrence’ relies on cognition of surveillance.

While the evidence provided by the video of Garner’s death would suggest a heinous miscarriage of justice, say researchers, the filming itself by a bystander would not generate the self-awareness and consequent behaviour modification during the incident as observed during Rialto’s institutionalised camera use.

“ ̽��ֱ��‘preventative treatment’ of body-worn-video is the combination of the camera plus both the warning and cognition of the fact that the encounter is being filmed. In the tragic case of Eric Garner, police weren’t aware of the camera and didn’t have to tell the suspect that he, and therefore they, were being filmed,” said Dr Barak Ariel, from the Cambridge’s IoC, who conducted the crime experiment with Cambridge colleague Dr Alex Sutherland and Rialto police chief Tony Farrar.

“With institutionalised body-worn-camera use, an officer is obliged to issue a warning from the start that an encounter is being filmed, impacting the psyche of all involved by conveying a straightforward, pragmatic message: we are all being watched, videotaped and expected to follow the rules,” he said.

“Police subcultures of illegitimate force responses are likely to be affected by the cameras, because misconduct cannot go undetected — an external set of behavioural norms is being applied and enforced through the cameras. Police-public encounters become more transparent and the curtain of silence that protects misconduct can more easily be unveiled, which makes misconduct less likely.” In Rialto, police use-of-force was 2.5 times higher before the cameras were introduced.

̽��ֱ��idea behind body-worn-video, in which small high-definition cameras are strapped to a police officers’ torso or hat, is that every step of every police-public interaction — from the mundane to those involving deadly force — gets recorded to capture the closest approximation of actual events for evidence purposes, with only case-relevant data being stored.

In Rialto, an experimental model was defined in which all police shifts over the course of a year were randomly assigned to be either experimental (with camera) or control (without camera), encompassing over 50,000 hours of police-public interactions.

̽��ֱ��dramatic reduction in both use-of-force incidents and complaints against the police during the experiment led to Rialto PD implementing an initial three-year plan for body-worn cameras. When the police force released the results, they were held up by police departments, media and governments in various nations as the rationale for camera technology to be integrated into policing.

Ariel and colleagues are currently replicating the Rialto experiment with over 30 forces across the world, from the West Yorkshire force and Northern Ireland’s PSNI in the UK to forces in the United States and Uruguay, and aim to announce new findings at the IoC’s Conference for Evidence-Based Policing in July 2015. Early signs match the Rialto success, showing that body-worn-cameras do appear to have significant positive impact on interactions between officers and civilians.

However, the researchers caution that more research is required, and urge police forces considering implementing body-worn-cameras to contact them for guidance on setting up similar experiments. “Rialto is but one experiment; before this policy is considered more widely, police forces, governments and researchers should invest further time and effort in replicating these findings,” said Dr Sutherland.

Body-worn cameras appear to be highly cost-effective: analysis from Rialto showed every dollar spent on the cameras saved about four dollars on complaints litigations, and the technology is becoming ever cheaper. However, the sheer levels of data storage required as the cameras are increasingly adopted has the potential to become crippling.

“ ̽��ֱ��velocity and volume of data accumulating in police departments — even if only a fraction of recorded events turn into ‘downloadable’ recordings for evidentiary purposes — will exponentially grow over time,” said Ariel. “User licenses, storage space, ‘security costs’, maintenance and system upgrades can potentially translate into billions of dollars worldwide.”

And, if body-worn cameras become the norm, what might the cost be when video evidence isn’t available? “Historically, courtroom testimonies of response officers have carried tremendous weight, but prevalence of video might lead to reluctance to prosecute when there is no evidence from body-worn-cameras to corroborate the testimony of an officer, or even a victim,” said Ariel.

“Body-worn-video has the potential to improve police legitimacy and enhance democracy, not least by calming situations on the front line of policing to prevent the pain and damage caused by unnecessary escalations of volatile situations. But there are substantial effects of body-worn-video that can potentially offset the benefits which future research needs to explore.”

Inset image: screenshot taken from a West Midlands (UK) officer's body-worn-camera.

As Obama pledges investment in body-worn-camera technology for police officers, researchers say cameras induce ‘self-awareness’ that can prevent unacceptable uses-of-force seen to have tragic consequences in the US over the past year — from New York to Ferguson — but warn that cameras have implications for prosecution and data storage.

An officer is obliged to issue a warning from the start that an encounter is being filmed, impacting the psyche of all involved by conveying a straightforward, pragmatic message: we are all being watched, videotaped and expected to follow the rules

Barak Ariel

Rialto PD

Screen capture from a Rialto PD officer's body-worn-camera

More information:

Ariel, B. et al. ̽��ֱ��Effect of Police Body-Worn Cameras on Use of Force and Citizens’ Complaints Against the Police: A Randomized Controlled Trial. Journal Quantitative Criminology (Nov. 19, 2014)

Read Dr Barak Ariel and Dr Alex Sutherland discuss the Rialto experiment and the future of body-worn-cameras on ̽��ֱ��Conversation US.

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