“Soft” policing at hot spots—do police community support officers work? A randomized controlled trial
“Soft” policing at hot spots—do police community support officers work? A randomized controlled trial
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DOI：
10.1007/s11292-016-9260-4
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发表时间：
2016-05
影响因子：
3
通讯作者：
B. Ariel;C. Weinborn;L. Sherman
中科院分区：
文献类型：
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作者：
B. Ariel;C. Weinborn;L. Sherman
ObjectivesTo确定增加警察巡逻在热点地区的减少犯罪的影响是否依赖于“硬”的直接人身逮捕的威胁，或是否“软”巡逻的平民（但穿制服）警察人员几乎没有逮捕权力，没有武器也可以减少犯罪。我们还试图评估是否离散巡逻访问的热点的数量是更多或更少的重要性比警察在场的所有访问的总分钟，以及是否基于犯罪计数的影响将是一致的犯罪危害指数outcome.MethodsWe随机分配到34个治疗单位和38个控制的72个热点。治疗包括增加徒步巡逻的穿制服，手无寸铁，警察社区支助官员（PCSO）谁不携带武器，并举行了几个逮捕权力超出了普通公民。该市每个PCSO和Constable上的GPS跟踪器都精确测量了所有热点的所有巡逻时间。标准化平均差（Cohen'sd）、OLS回归模型和加权位移商分别用于评估主效应、模拟GPS数据与治疗的相互作用效应以及测量干预的获益扩散。结果包括计数的事件以及剑桥犯罪危害指数。ResultsAs预期的，巡逻访问和分钟的警察是平等的治疗和对照组。治疗组之间的唯一监管差异是PCSO对热点的访视，包括离散访视的平均每日频率（T = 4.65，C = 2.66;p≤ .001）和所有访视的总分钟数（T = 37.41，C = 15.92;p≤ .001），治疗组每天的10分钟访视比对照组多约2次。主效应估计表明，通过对报告的犯罪进行差异分析，与对照组相比，犯罪率降低了39%，与对照组相比，紧急呼叫服务减少了20%。与对照组相比，周边地区的犯罪显示出治疗热点的利益扩散，而不是流离失所。观察到“赖斯奖励”效应，更积极主动的巡逻预测减少犯罪的治疗热点，而更多的反应PCSO时间预测更多的犯罪控制热点。犯罪危害指数估计的犯罪预防的严重性价值的范围从85至360个潜在的监禁天，在每个治疗组的热点（相对于对照组）的平均差异为21分钟以上的PCSO巡逻，每天的潜在投资回报率高达26比1.ConclusionsA犯罪减少的影响，在热点的额外巡逻是不以“硬”警察权力为条件。即使是在徒步巡逻显示“软实力”的手无寸铁的准专业人员，不断举行车辆巡逻的警察，有因果关系，既较低的犯罪计数和犯罪伤害指数得分大幅降低。治疗组内的相关证据表明，更频繁的离散PCSO访问可能会产生更多的减少犯罪的好处比更长的访问时间，但随机对照试验需要更好的证据在这个关键问题。
ObjectivesTo determine whether crime-reduction effects of increased police patrols in hot spots are dependent on the “hard” threat of immediate physical arrest, or whether “soft” patrols by civilian (but uniformed) police staff with few arrest powers and no weapons can also reduce crime. We also sought to assess whether the number of discrete patrol visits to a hot spot was more or less important than the total minutes of police presence across all visits, and whether effects based on counts of crime would be consistent with effects on a Crime Harm Index outcome.MethodsWe randomly assigned 72 hot spots into 34 treatment units and 38 controls. Treatment consisted of increases in foot patrol by uniformed, unarmed, Police Community Support Officers (PCSOs) who carry no weapons and hold few arrest powers beyond those of ordinary citizens. GPS-trackers on every PCSO and Constable in the city yielded precise measurements of all patrol time in all hot spots. Standardized mean differences (Cohen’sd), OLS regression model, and Weighted Displacement Quotient are used to assess main effects, to model the interaction effect of GPS data with treatment, and to measure the diffusion-of-benefits of the intervention, respectively. Outcomes included counts of incidents as well as the Cambridge Crime Harm Index.ResultsAs intended, patrol visits and minutes by Police Constables were equal across the treatment and control groups. The sole difference in policing between the treatments groups was in visits to the hot spots by PCSOs, in both the mean daily frequency of discrete visits (T = 4.65, C = 2.66;p≤ .001) and total minutes across all visits (T = 37.41, C = 15.92;p≤ .001), approximately two more ten-minute visits per day in treatment than in control. Main effect estimates suggest 39 % less crime by difference-in-difference analysis of reported crimes compared to control conditions, and 20 % reductions in emergency calls-for-service compared to controls. Crime in surrounding areas showed a diffusion of benefits rather than displacement for treatment hot spots compared to controls. A “Reiss’s Reward” effect was observed, with more proactive patrols predicting less crime across treatment hot spots, while more reactive PCSO time predicted more crime across control hot spots. Crime Harm Index estimates of the seriousness value of crime prevented ranged from 85 to 360 potential days of imprisonment in each treatment group hot spot (relative to controls) by a mean difference of 21 more minutes of PCSO patrol per day, for a potential return on investment of up to 26 to 1.ConclusionsA crime reduction effect of extra patrols in hot spots is not conditional on “hard” police power. Even small differences in foot patrols showing the “soft power” of unarmed paraprofessionals, holding constant vehicular patrols by Police Constables, were causally linked to both lower counts of crimes and a substantially lower crime harm index score. Correlational evidence within the treatment group suggests that greater frequency of discrete PCSO visits may yield more crime reduction benefit than greater duration of those visits, but RCTs are needed for better evidence on this crucial issue.