Objectives

This paper examines whether the posting of sticker decals indicating the use of forensic property marking deters burglary.

Methods

The study is a randomized controlled trial (RCT). The sampling frame includes all (N = 6603) single-family houses in the municipality of Aarhus, Denmark, that were burgled once or more during the 4 years prior to the experiment. Houses were randomly assigned to treatment (n = 3378) and control (n = 3225). Treatment houses were offered a free forensic property marking kit and asked to post sticker decals around their front doors indicting their use of the product. Control households were not contacted.

Results

A process evaluation determined that only one-third (n = 1080) of the houses assigned to treatment requested property marking kits and posted stickers as instructed. An intention-to-treat (ITT) effect analysis was based on the full treatment group despite a low (32%) compliance rate. At the end of a 15½-month observation period, the full treatment group had experienced 21% fewer burglaries than the control group – a difference that is both substantively and statistically significant (χ² = 5.305, p = 0.021 n = 6608). Analysis revealed that the preventive effect was limited to the beginning of the observation period and declined thereafter. It is therefore possible that some of the overall result may have been due to an “availability effect,” i.e., a heightened vigilance induced by the initial contact letter.

Conclusions

The preventive effect of treatment seems incontestable. This said, the full pattern of results suggests that the reduction in burglary was likely due to a combination of treatment and availability effects.

中文翻译：

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指示使用法医标记的贴纸是否可以防止盗窃？随机对照试验的结果

目标

本文研究了是否贴有指示使用法医标记的贴纸贴花可以防止盗窃。

方法

该研究是一项随机对照试验（RCT）。抽样框架包括 丹麦奥尔胡斯市所有（N = 6603）单户住宅，这些住宅在实验前的4年内被盗窃一次或多次。将房屋随机分配给治疗组（n  = 3378）和对照组（n  = 3225）。为治疗室提供了免费的法医财产标记工具包，并要求其在前门周围张贴贴纸贴花，以指示他们使用该产品。没有联系控制家庭。

结果

一项过程评估确定， 分配给治疗的房屋中只有三分之一（n = 1080）要求提供属性标记套件并按照指示贴上贴纸。尽管依从率低（32％），但意向治疗（ITT）效果分析是基于整个治疗组的。在一个15½个月的观察期结束时，充分治疗组经历了比对照组少盗窃21％ -的差即实质和统计学显著（χ ²  = 5.305，p  = 0.021  Ñ = 6608）。分析表明，预防作用仅限于观察期的开始，随后逐渐下降。因此，总体结果中的某些结果可能是由于“可用性效应”引起的，即由初始联系信引起的提高的警惕性。

结论

治疗的预防作用似乎是无可争议的。这就是说，完整的结果表明，入室盗窃的减少可能是由于治疗和利用效果的综合作用所致。