Table 2 - uploaded by Gohar A. Petrossian
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One-way analysis of variance (ANOVA) summary table comparing experimental and control viewsheds on crime occurence per viewshed area Source df SS MS Fp Auto theft
Source publication
We present a test of the crime-deterrent effect of police-monitored street-viewing CCTV cameras using viewsheds of areas that
were visible by cameras via direct line-of-sight and that were digitized using easily replicable methods, Google Maps, and
standard GIS tools. A quasi-experimental research design, using camera installation sites and randoml...
Context in source publication
Context 1
... 1 compares means and standard deviations of crimes occurring within each viewshed area. As shown in Table 2, results failed to reach statistical significance for auto theft and theft from auto, while results for shootings were statistically significant. The effect sizes for March/Control, July/Control, and March/July viewshed areas were 0.06, 0.62, and 0.69, respectively. ...
Citations
... On the other hand, violent crime, such as weapons offenses and aggravated assault, tend to target specific individuals or locations. Although surveillance cameras cannot ultimately eliminate problems, they have meaningful deterrence effects (Caplan et al. 2011;Ratcliffe et al. 2009). Thus, the installation of CCTVs can effectively protect potential victims in these instances. ...
... Currently, the primary focus of research on CCTV target areas is to explore and develop effective selection methods. For example, Vilalta et al. (2019) studied the relationship between CCTV and crime in Mexico by using census tracts as target areas; Caplan, Kennedy, and Petrossian (2011) assessed the impact of CCTV on shootings and car theft in Newark, New Jersey, by comprehensively applying Google Maps and geographical information system tools to define CCTV vision and using it as the target area. Lim and Wilcox (2017) used the WDQ algorithm to assess the effect of CCTV in open areas in Cincinnati, Ohio, by using a circular region around the CCTV as the target area and considering building occlusion. ...
... found a more nuanced set of results; they showed that the effects of firearm dealers on shootings were suppressed in a citywide analysis, while it did have significant and strong attractive effects in disadvantaged neighbourhoods. CCTVs were found to have a decreasing effect in areas with already low crime rates, but in the whole city of Newark no significant effect could be found (Caplan, Kennedy and Petrossian 2011). The presence of gang graffiti, both in threatening and nonthreatening form, was shown to have an increasing effect on gang homicides by Hughes, Schaible and Kephart (2021). ...
... Policing. Police-monitored closed-circuit television (CCTV) can be used to deter crimes, but the placement needs to be carefully evaluated and the effect should not be measured as an average for the city (Caplan, Kennedy and Petrossian 2011). Summers and Johnson (2017) highlight that interventions such as CCTVs and police patrols should include streets adjacent to main streets in their coverage in order to effectively suppress 'outdoor severe violence'. ...
This article reviews five decades of literature in English investigating the nature of locations where most firearm-related violence occurs in public places, with a focus on neighbourhood-level and land-use characteristics. A search for peer-reviewed articles in Scopus, Web of Science and PubMed from 1970 to 2022 resulted in 112 articles. A bibliometric followed by a thematic analysis of the articles shed light on two questions: Which types of neighbourhood characteristics attract firearm-related violence? and What are the typical land uses associated with firearm-related violence? The article concludes by reporting examples from research of safety interventions implemented to tackle firearm violence.
... It is now possible to monitor and record video in various public places using computer-based CCTV cameras. CCTV cameras are used for a wide range of purposes such as monitoring of class and examination, security, and tracking criminal activities [5,6].Another example would be video surveillance in bad weather, such as heavy rain, fog, or snow and low illumination using CCTV cameras. Due to the hindrance produced by weather elements, the CCTV camera may collect images with diminished contrast and quality in such scenarios [7]. ...
Image enhancement and reconstruction is an important field of research in digital image analysis. To increase the quality of low-contrast images, a variety of image-enhancing technologies are available. Among these image enhancement techniques, singular value decomposition and discrete wavelet transform are the popular approaches for enhancing low-quality images. In this study, we have developed a modified singular value decomposition approach to enhance low-contrast and low-resolution close-circuit television images. Low-quality and low-resolution images with singular values near zero are used as input in the proposed approach. On the selected data, a threshold value was determined in the singular values of the diagonal matrix. Finally, the proposed modified singular value decomposition technique was applied to enhance the value of images with low quality and resolution. The datasets include 90 facial images of different individuals with low quality and resolution from a university database. The performance of the proposed approach is assessed using image entropy, peak signal to noise ratio, mean square error, contrast measurement and time computation. During the experiments performed on the obtained dataset, it was found that the proposed modified singular value decomposition approach outperformed the existing singular value decomposition, discrete wavelet transform-singular value decomposition and stationary wavelet transform methods.
... Criminal Justice Policy Review,33(8), 7 crime (Alexandrie, 2017;Piza et al., 2019;Welsh & Farrington, 2009), the effects vary by location and crime type. Most studies report significant reductions in vehicle and property crimes (Alexandrie, 2017;Caplan et al., 2011;Piza et al., 2014;Piza, 2018), while only a few have found a significant reduction in violent crimes (Piza et al., 2014), especially in cases of unruly spectator behavior in sports arenas (Priks, 2014) and robberies at train stations (Priks, 2015). ...
... For example, Van Houten et al. (1980) found that the use of a salient sign on a roadside decreased speeding. Caplan et al. (2011) found that increased visibility of CCTV cameras decreased criminal behavior, and McNees et al. (1976) used salient signs with success to decrease shoplifting. Knowing that the salience of the dog changes when it is present in the environment and wearing or not wearing a jacket might be important information for law enforcement. ...
Detection dogs are used at border controls as an antecedent intervention to deter the smuggling of contraband. However, there is little research that has explored how the presence of dogs might affect passenger behavior. We observed passengers' behavior at a port when there was an officer alone, an officer with a dog, and an officer with a dog wearing a florescent yellow jacket with "police" written on it for increased salience. We measured eye contact, vocal-verbal interactions, facial expressions, and nonvocal verbal gestures toward the officer and dog, and changes in passenger direction. Passengers looked, talked, and had the highest frequencies of positive facial expressions when the dog was not wearing a jacket. However, passengers looked toward the dog the quickest and had the highest frequency of negative facial expressions and gestures when the dog was wearing a jacket. We discuss how these findings might inform antecedent interventions to address undesirable behavior such as smuggling.
... One study argues by analogy to murder and rape, that CCTV systems do not deter burglars "since many burglaries could occur out of a camera´s view" (p. 264, Caplan et al., 2011). We disagree. ...
Do informal and formal mechanisms of guardianship work together to reduce residential burglary? In this article we argue that informal guardianship moderates the relationship between formal mechanisms of guardianship and residential burglary. Formal guardian-ship requires some level of social cohesion and trust to be effective against residential burglary. We test this argument with the use of robust panel quantile methods controlling for time effects, spatial effects, and alternative explanations. Using Mexico City neighborhood crime and census data, we show evidence of a moderating weakening effect of informal guardianship on the previous relationship, particularly in deprived neighborhoods and only in the upper quantiles of the residential burglary distribution. In addition, the moderation effects seem to have weakened over time. In sum, the combination of guardianship mechanisms seems to have been more effective in high burglary risk deprived neighborhoods, although their combination seems to have become less relevant.
... According to Deterrence theory, police monitored CCTV systems are employed for crime prevention because they enhance the risk of detection and arrest (Clarke, 1992;Liedka et al., 2019;Welsh & Farrington, 2008), causing potential offenders to weigh the risks and advantages of offending. The scientific literature is divided on the usefulness of police-monitored CCTV systems, with some research stating that these systems are effective in reducing crime (Brown, 1995;Lai et al., 2019), and the majority having mixed results (Armitage, 2002;Caplan et al., 2011;La Vigne et al., 2011;Liedka et al., 2019;Lim et al., 2016;Phillips, 1999;Piza, 2018;Piza et al., 2014;Ratcliffe et al., 2009). In terms of preventing property crimes, one city case study in China discovered that surveillance cameras influence street robbers' crime location choice, even though the guardianship effect of ambient population (i.e., people who live or work near where a crime occurs) is bigger than that of law enforcement surveillance cameras. ...
... Our results are neither consistent with those studies reporting mixed results on the effectiveness of police monitored CCTV systems (Armitage, 2002;Caplan et al., 2011;La Vigne et al., 2011;Liedka et al., 2019;Lim et al., 2016;Phillips, 1999;Piza, 2018;Piza et al., 2014;Ratcliffe et al., 2009) nor with studies reporting these systems as effective in reducing crime (Brown, 1995;Lai et al., 2019). Although delivery robbery rates reduced between 2019 and 2021, there is no evidence connecting these decreases to the MiCalle programnot in the MiCalle program's so-called Priority neighborhoods nor in the factually Treated neighborhoods. ...
Objectives: Police-monitored CCTV systems are supposed to reduce on-the-street crime. The purpose of this study is to determine whether the MiCalle CCTV systems program in Mexico City had local and spatial spillover effects on delivery robberies. Methods: When data is clustered in space and time, random effects and errors can be autocorrelated in both dimensions. To test the effectiveness of the MiCalle program on delivery robbery crime rates, a Difference-inDifferences (DID) design was specified in a maximum likelihood (ML) panel regression model with spatial lag coefficients, random effects variance estimates, and autoregressive serial correlation variance estimates. Results: At the neighborhood level of study, we find no evidence connecting delivery robbery crime rates to the Mexico City MiCalle program. Conclusions: The MiCalle program has been geographically unfocused and appears to have been ineffective in reducing delivery robberies. Future studies of police-monitored CCTV systems should consider the possibility of spatiotemporal interactions among variables, particularly if spatialized panel data is used.
... CCTV has a central place in crime control technology (Armitage et al., 1999) but it is argued that it can lead to a decrease, an increase or no change in crime in the decent level of scientific rigour and therefore the overall results seem clear and unambiguous. Other studies show successful prevention (Tilley, 1993;Armitage et al., 1999;Ditton & Short, 1999;Farrington, Bennett et al., 2007;Ratcliffe et al., 2009;Caplan et al., 2011; but also undesirable results (Gill & Spriggs, 2005;Gill et al., 2006) and no effects or mixed effects (Sivarajasingam et al., 2003;Gill et al., 2006;Lim et al., 2016) or crime displacement (Brown, 1995;Fyfe & Bannister, 1996;Cerezo, 2013). ...
... Findings from evaluations also suggest that CCTV effects are contextual, influenced by a camera's environmental backcloth, line-of-sight, ability to generate proactive enforcement, setting and the targeted crime type (Caplan et al., 2011;Piza et al., 2014Piza et al., , 2019Lim et al., 2016). ...
... For instance, in the study by Lee et al. (2016) in Seoul, 12 neighbourhoods were selected as treatment areas, and 12 adjacent neighbourhoods were selected as the comparison group. In Newark, Caplan et al. (2011) treated locations of CCTV cameras as treatment areas and randomly selected comparison areas to assess their impact on crime prevention. Instead of creating concentric buffers, view sheds from cameras were designated. ...
Based on data from eight Polish cities, we tested if closed-circuit television (CCTV) monitoring systems are effective in crime reduction and if the CCTV monitoring effects are durable. In a quasi-experimental method, we applied police data about four types of crime incidents in 2005–2014 as well as camera location. A preventive effect appeared in 10 of 17 of analysed paired treatment/comparison areas. The overall mean effect appears modest. In two of four cases, the preventive effects were durable. The analysis proves that CCTV cameras in the Polish cities had a crime reduction effect and the effect is sensitive for the category of crime. The influence of CCTV on the fall in crime in Poland is unlikely.
... taking into account that several participants may report the same location). The reason that the labels "Park/green area" and "Industrial area/construction site/harbor" are applied to both polygons and points is that, in these cases, points refer to a specific location within, for instance, a park a Percentages may not total 100 due to rounding in similar previous research in a European context (e.g., Hardyns et al. 2019;Stanković, 2021), and corresponds to roughly twice the median (172 m) and mean (228 m) length of inner-city blocks in Malmö, similar to the operationalization of "behavioral settings" by Caplan et al. (2011). The grid includes a total of 4031 cells, which also represent the operationalization of micro-places in the current study. ...
Objectives
To explore the extent to which unsafe locations are concentrated to micro-places within the city of Malmö, Sweden, and whether there is a temporal stability in these micro-places over time.
Methods
Information on unsafe locations is obtained from an open-ended item across three waves of a random sample community survey. Reported unsafe locations are geocoded as polygon, polyline, and point features and merged with a 200 by 200-m grid-cell network using both unadjusted and weighted counts.
Results
The results suggest that unsafe locations are concentrated to a small share of grid-cells using different metrics. There are also signs of spatial clustering and a temporal stability of unsafe locations over time.
Conclusions
As unsafe locations are concentrated to a small share of micro-places the results have important implications for both theory and practice. However, further research exploring unsafety and fear of crime at micro-places is highly warranted.
... CCTV effectiveness requires quantifying the benefits of crime prevention, i.e., a decrease in the number of crime incidents. In most cases, the crime prevention function of CCTV surveillance systems seems to be apparent (Armitage et al., 1999;Caplan et al., 2011;Ditton et al., 1999;Farrington et al., 2007;Ratcliffe et al., 2009;Tilley, 1993). A systematic review of studies focused on CCTV surveillance systems (Piza et al., 2019) shows that, in general, CCTV is associated with a decrease in crime incidence. ...
... The effects, however, seem to be uneven across the various types of crime and differing locations. Some studies offer ambiguous results, which depend on crime type and other contextual/environmental factors (Caplan et al., 2011;Gill et al., 2006;Lim et al., 2016;Piza et al., 2014b;Priks, 2015;Sivarajasingam et al., 2003). For instance, CCTV's most extensive and most consistent effects were observed in car parks for area-specific crime types, whereas no significant effect was observed for violent crimes (Piza et al., 2019;Welsh et al., 2015a, b). ...
Closed-circuit television (CCTV) surveillance has been increasingly popular worldwide as a crime prevention measure, while its effectiveness, efficiency, and related privacy issues are debated. In this paper, we investigated whether the municipal CCTV surveillance system is cost-effective in the case study of Poznan, Poland. The analysis comprised (a) the preventive effectiveness of CCTV, (b) costs of CCTV surveillance system installation and operation, and (c) costs of crime. We collected police data on three categories of street crimes: (a) car burglary/theft, (b) car damage, and (c) robbery, as well as data on the costs of CCTV surveillance system construction and maintenance. We searched for a year after installing the CCTV system when the accumulated, hypothetical financial cost of crime was higher than the actual accumulated cost of crime and CCTV installation and maintenance in any treatment area. The number of crimes in a given category was predicted based on a comparable control area, where there were no cameras. Our study suggests that CCTV surveillance is cost-ineffective in most areas. This result implies the cautious development of CCTV surveillance, taking into account the target crime types and costs, including social costs and benefits. Evaluating cost-effectiveness, although considered as a robust measure, is in practice difficult. However, analysis of the correlation between land use characteristics and cost-effectiveness may provide practical advice on where to develop CCTV surveillance monitoring.
