The retail sale of cannabis in coffee shops is tolerated in the Netherlands, provided that certain criteria are met. Two criteria were added in 2012: the private club and the residence criterion. The plan was to implement them first in the southern provinces and later in the other provinces. This created an opportunity for a natural experiment. In an experimental group of seven municipalities in the south and a matched comparison group of municipalities in the other part of the country pre- and post-measurements were conducted. The size of the drug tourism, the number of visits to coffee shops, the illegal cannabis consumer market and the nuisance experienced in the direct vicinity of coffee shops was assessed. Robust changes occurred in the experimental group after implementation of the new criteria. Initial differences between the groups and variation in local implementation caused doubts about drawing causal conclusions. This article analyzes whether such conclusions can be drawn. We conclude that due to the broad design of the research it appears that the observed changes can be attributed to the new criteria despite the methodological shortcomings in the study.

This paper examines the relationship between imprisonment length and registered recidivism. The data come from a unique longitudinal and nationwide study of Dutch male prisoners, serving an average of 4.1 months of confinement (N=1,467). Ideally an experimental design would be appropriate to examine the influence of different sentence lengths on recidivism. In order to approximate such a design using observational data, we adopt a propensity score methodology to control for selection bias in the dose-response relationship. Using a six-month follow-up, we do not find significant differences in post-release recidivism between men who spent shorter or longer periods of time in confinement. We discuss the pros and cons of the methodology applied as well as potential implications of the findings.

Valid interpretation of quasi-experimental effect evaluation studies using propensity score matching is in need of a more detailed coverage of non-matched cases in both experimental and comparison group. The argument is illustrated using a number of recent Dutch criminological studies.

This study investigates the effect of providing information about decision making on aggression of clients of the Dutch Employee Insurance Agency (UWV). The expectation is that providing adequate information leads to a decrease in aggression, because it influences feelings of informational justice and frustration. UWV-clients (N=1.415) participated in an experimental scenario study (adequate vs. limited information providing). Next to aggression, psychological, UWV and social demographic characteristics were measured. Compared to limited information, receiving adequate information results in lower aggression. Clients with more negative affect show more aggression, but receiving adequate information especially reduces aggression in these clients.

The current vignette experiment among 414 students in the Netherlands explores the effect of the police response on willingness to cooperate and examines whether this relationship is mediated by perceptions of the legitimacy of the police. This is done based on Tyler’s procedural justice theory and previous research among crime victims. The police response in the vignette was manipulated in two ways: the police offered a fair/unfair treatment and had/had not performed investigative actions. There was no police contact in a control group. The results suggest a positive effect of the police response on willingness to cooperate and imply that this relationship is mediated by perceived trust in the police.

Previous research showed that job applicants with a criminal record have lower chances of obtaining employment compared to job applicants with no criminal record. At the same time empirical studies showed that having a job is especially beneficial for ex-delinquents, as employment was found to lower recidivism. The current study uses an experimental design to look into the influence of a criminal record on employment chances. For this purpose, 520 resumes and motivation letters were sent in response to vacancies published on the internet. All were identical except for the stated offence type (no offence, violent offence, property offence, or sexual offence), duration between conviction and application, business sector and ethnicity of the applicant. Results show no effect for type of offence or no offence on employment chances. However, a strong effect is found for ethnicity. Ethnic minorities with no conviction were even found to have lower chances of receiving a positive reaction compared to applicants with a Dutch name and a conviction for a violent offence.

In a vignette study, we investigated the extent to which factors may mitigate the relative ‘unattractiveness’ of one-time offenders as cohabitation partners. These factors include having a job, not having a criminal record and the amount of time that has passed since the offence was committed. This was done by asking students to advise a hypothetical person whether he or she should start cohabiting with his or her partner who had offended once. The factors of interest were systematically varied. Our findings showed a more positive cohabitation advice when the offender had committed the offence relatively long ago. Our findings also showed a more positive cohabitation advice when the offender was employed. This is an important finding, as this may indicate that being employed also helps ex-offenders getting their lives back on track with respect to cohabitation.

Mobile identification techniques will, in the near future, make it possible to rapidly analyze DNA and fingerprint traces during a crime scene investigation, compare them with reference samples, and use the results in the investigation. In this experimental study the influence of these rapid analysis results on the formation of hypotheses, and of database matches in these results on the interpretation of traces by Crime Scene Investigators (CSIs) in the Netherlands was studied. A group of CSIs (N=65) conducted a simulated crime scene investigation. The analysis results as well as the moment these were provided were manipulated. The results show that the analysis results influence the formation of hypotheses by CSIs, and that this influence is time-dependent. Judgments by CSIs regarding the importance of traces were shown not to be influenced by database matches.

Eyetracking enabled the authors to study eye movements of 23 participants who looked at crime scene photographs. The authors measured the emotions elicited by the photographs, as well as perceptions of seriousness and the sentence that participants would give the perpetrator of the crime. Also, individual differences in disgust sensitivity were taken into account. Results show a positive relationship between disgust sensitivity and both the proportion of fixations as well as the number of fixations on gruesome aspects of the photos (the blood and the wound), emotion ratings of the photographs, perceptions of seriousness, and the sentence given. Implications, limitations, and future directions of the research are discussed.