In the investigation into the murder of lawyer Derk Wiersum, a cousin of Ridouan Taghi, who was arrested in Morocco, is also in the picture of the police and the judiciary. Jaouad F. (27) from Nieuwegein was arrested in October because he is suspected of involvement in the mistaken murder of the son of a Moroccan judge in Marrakech (2017).

According to the judiciary, Jaouad F. communicated frequently with Anouar Taghi and a few others about preparations for the murder of Wiersum. Website NU.nl writes that this became apparent on Friday during an interim session in the case against Anouar Taghi (another cousin of Ridouan Taghi) and some co-defendants in the Amsterdam court. The Public Prosecution Service suspects Anouar Taghi and co-suspects of involvement in the preparation of the murder and participation in a criminal organization.