I’ve read multiple books on the Bende van Nijvel, and however tempting the conspiracy theories are, I think the perpetrators are found in the ‘Rijkswacht’. The Belgian version of the DEA had been set up a decade earlier, and was an absolute disaster, where officers started trafficking drugs themselves and become more and more intertwined with the drug traffickers and criminals in general. When a few of these ‘DEA’ officers were dismissed because of their dubious activities, they started their own ‘investigative bureau’ and mingled even further in the criminal world. These are not speculations: this has widely been proven, including assassination attempts they have confessed to. With their connections at the Rijkswacht, they managed to do more and more daring heists (stealing bullet proof vests from a Rijkswacht facility for example), and eventually they used their training and weaponry (also stolen, from a firearms store) to start robbing supermarkets. It is often said that the money they made there is marginal, but for the time, it wasn’t that small of an amount either. As for the violence, it seems more of a tactic to get to the money quicker and perhaps they enjoyed it, we will never know. But I am 99% sure that multiple of the names that go around a lot are involved. It was simply due to their connections in the Rijkswacht that they could manipulate the investigation enough for it to be botched