Between 1984 and 1986, 20 bombs exploded across Luxembourg - from blown up electricity pylons to explosions at gendarmerie offices to airport radar equipment and the roof of the Coque swimming pool. No one was killed, but the material damage was tremendous.

The criminal individual or group of criminals (their composition was never clear) became known as the Bommeleeër, the "bomb planters", also known as the Bomber's Affair. Arguably the largest criminal chapter in Luxembourg’s history, and since World War II the biggest threat to the capital.

Ransom letters were sent, money was demanded, but never paid. Used in all of these attacks was the Luxembourg-made explosive Luxite. Nearly 500kg of the material was stolen from a factory.

Part 1 of this two-part series reveals the complexity of an investigation spanning several decades, a mystery still unsolved today. Some very uncomfortable accusations and theories came to see the light of day. Involvement of the secret service, and the likelihood of a mole inside the police force were much-discussed theories. Moreover, there was the assumption that Luxembourg's royal family may have been involved. Was this a state secret?

Listen to this week's episode of DNA: Luxembourg Crime Podcast:

Podcast

The criminals were always one step ahead. They even attacked the offices of the investigators on the case, whose names had never been shared publicly. A scary time to be involved in this investigation as a politician and police officer.

Let us start by unpacking the events in chronological order and try to connect the dots. Maybe you, our DNA audience, can already spot something in this summary that investigators may have missed along the way?