Background Pattern

JADS students make remarkable discovery in police investigation

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Since 2021, students from JADS have been helping the police in the cold case of the murder of Marja Nijholt. In this project, JADS students analyzed telecom data that was shared with them – in pseudonymised form – by the Oost Brabant Police.

In 2020, the cold case of Marja Nijholt was taken off the shelf by the citizens’ collective Bureau Dupin. A group of creative researchers (including technicians, taxi drivers, teachers, researchers, students and artists) formed a collective to check all the clues in this case, hoping to gain new insights. The idea of ​​Bureau Dupin is to apply a new methodology when solving cold cases: using the wisdom of the crowd. Every citizen can participate.

The members of the investigative collective are assisted in their investigation by the police, the judiciary and the Public Prosecution Service. This is unique, because these organizations have never collaborated  before with a group of investigating citizens.

Retrieving information from telecom patterns

The police shared a dataset with thousands of telephone records in the months before and after Nijholt’s death. This set also contains Nijholt’s telephone contacts. Because the data is pseudonymised for privacy reasons, data can not be traced back to individual telephone numbers and names.

However, it is possible to analyze such a dataset and retrieve information about telecom patterns and locations. Data science students from the Jheronimus Academy of Data Science in Den Bosch took on this task. Assisted by professor of practice Peter de Kock and telecom specialist René Pluijmers, they made a remarkable discovery.

The JADS students found out that Marja Nijholt most likely had not one but two telephones in use. This is remarkable because this had not previously emerged in the study and raised questions that the police haven’t asked before.

Making data tools available for the crowd

The JADS students have also developed software programs that allow other members of the Bureau Dupin community to independently analyze the data. Community members can follow a ‘masterclass’ on the online forum (or look back) in which telecom expert René Pluijmers explains to them how to use these software programs: This software brings modern data science together with the substantive knowledge of other members.

Collaboration JADS and Oost Brabant Police

The success of the involvement of JADS students in police investigations is apparent from the new agreement between the JADS and the East Brabant Police Unit. The police plans to ask the assistance of JADS students more frequently. Data science is a relatively young field and having access to the best and newest techniques in this field is a valuable asset for the police.

Podcast and documentary series

Bureau Dupin’s investigation is still ongoing. Do you want to know more about the research? Then listen to the podcast series ‘De New Years Murder’ and ‘Op het Bureau’ in your favorite podcast app. In the autumn of 2022, Videoland will broadcast a four-part documentary series about this research. Do you want collaborate or are you just curious? Then go to

Want to know more about the New Year’s Murder and the investigation? Tilburg University’s independent news medium Univers published an interview with Peter de Kock.

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