FORmidable FORensics

ATM bombers have been using more and stronger explosives. The result: the ATMs targeted are utterly destroyed, and enormous damage is done to surrounding property. In this case, the police arrived to find collapsed walls and broken windows.

Scattered amongst the debris they found what was left of the explosive device: detonator splinters, tape fragments, cables – it was a puzzle made up of seemingly incongruous pieces.

Putting these pieces back together again is the FOR’s specialty. Their work contributes significantly to the success of these investigations.

Freeze!

In 2021, the FOR was called to the scene of 19 ATM bombings. Before the team starts securing evidence, everyone’s got to “freeze!” – nobody moves until the bomb disposal specialists* have identified any possible dangers and diffused them. It happens all the time that criminals leave explosive charges behind, either because they were interrupted and fled the scene, or because the device failed to detonate.

Usually, however, there is hardly anything left of the explosive. The various chemicals involved are broken down in the blast. What remains is a fine residue that is invisible to the naked eye. The FOR specialists are able to preserve these microscopic traces, and use cotton rounds to collect the residue.

The evidence is later examined in a laboratory. The aim is to identify the chemical composition of the explosive, and to reconstruct the explosive charge.

Debris and ash become investigation leads

This information provides fedpol investigators with clues as to the group responsible for the ATM explosion, and whether there are any connections with other cases. Previous investigations have shown that the criminal groups active in Switzerland specialise in specific explosive methods. In 2021 the FOR recovered the following evidence at several crime scenes:

• Fragments of explosive devices indicating the ‘pizza slide method’ was used (explosive devices are inserted into an ATM using one or several metal poles).

• Fragments of detonators meant for a different, harmless purpose were instead used to build an improvised explosive device.

With the help of chemical analyses and microscopes, the FOR specialists reconstruct ATM bombings, piece by piece, generating valuable leads for fedpol’s investigation from a pile of debris and ash.