Court sentences harsher after defense lawyer's murder, but only for Moroccan suspects
In the weeks after the murder of defense lawyer Derk Wiersum, Dutch judges imposed harsher sentences, but only on suspects of Moroccan descent, Trouw reports based on joint research by the University of Gothenburg, Vrije Universiteit Amsterdam, and Erasmus University Rotterdam.
Compared to the period before Wiersum’s assassination in September 2019, court sentences were on average 71 percent higher. This translated into convicts serving an average of three months longer in prison. This exclusively affected suspects of Moroccan descent. For suspects of Dutch or Turkish-Dutch descent, there was no difference in sentences before and after the Amsterdam lawyer’s murder.
According to the researchers, this is the “salience effect” - subconscious extra attention for characteristics that receive a lot of media attention. After Wiersum’s murder, Dutch media emphasized that he was assassinated because he represented a key witness in the criminal case against Dutch-Moroccan Ridouan Taghi. Terms like “Mocro Mafia” were widely used in the reporting around the lawyer's death.
The harsher sentences affected 384 suspects of Moroccan descent who were sentenced to prison by a Dutch judge. When media attention decreased after a few weeks, the prison sentences for Moroccan suspects also returned to the typical length they had before his murder.
Researcher Olivier Marie, a professor at Erasmus University, stressed that judges have some discretion within the law to determine the appropriate sentence for a specific suspect. “In the aftermath of a major societal shock, it can’t hurt to have a fellow judge weigh in on a verdict. Or have a computer program compare the sentence with previous rulings. Then the judge can ask themself whether they are certain they want to impose an above-average sentence.”
Two men were convicted of Wiersum’s assassination and sentenced to 30 years in prison in 2021. The appeals court and Supreme Court upheld the sentence in 2023 and 2024. Neither of the conflicts is of Moroccan descent.
The “salience effect” has long been known in science, but this is the first time it has been studied in Dutch criminal cases. The Researchers will soon publish their results in the scientific journal American Economic Review.
