Remember, remember the fifth of November
Gunpowder, treason and plot.
I see no reason, why gunpowder treason
Should ever be forgot.
On the 5th of November 1605, Guy Fawkes was discovered in a cellar below the UK Parliament buildings, poised to ignite 2500 kg of gunpowder. It was enough material to blow up the entire Palace of Westminster and kill everyone within a 100 meter radius.
While not the only culprit by any means, Fawkes has become the most famous of the Gunpowder Plot conspirators and to this day, Britons celebrate this failed assassination attempt (on King James I) by burning effigies of Guy Fawkes on giant bonfires and hosting breathtaking firework displays up and down the country.
Unsurprisingly, explosives are an even hotter (pardon the pun) topic today than they were back then. To best prepare you for this annual tradition, we provide a compelling insight into the forensics of explosives.
Take a seat: the characteristic damage caused by an explosive.
Visualise a single drop of water falling into a still pond: the ripples that you see are easily likened to the effects of a bomb blast. The initial blast wave of highly compressed air and shrapnel is the most damaging. Depending on the type of explosive, this phenomenon can cause significant damage to both property and life. Shockwaves that follow, while less damaging, can compound the existing destruction.
Explosions cause very specific damage to the surrounding area which makes it possible for investigators to determine the seat or origin of the blast. Buildings, objects or people closest to the epicentre — for instance — will suffer the most significant damage or loss of life. Fragments of glass, debris and other objects nearer to the explosion can be pulled back into its seat, but only once the void left by the sudden expulsion of air refills. Understanding the dynamics of an explosion is crucial in order to reconstruct the sequence of events.
Stepping through debris: bomb reconstruction with fragments.
The scene left behind by an explosive blast can be very large depending on the type of explosive used. Nevertheless, it is crucial for investigators to search the entire area so that every piece of the bomb can be recovered, from the casing to the detonator — even the timer. These fragments could be anywhere — the tops of roofs, beneath cars and even embedded in blast victims.
Once all the fragments have been collected, explosive device specialists can reconstruct the device to reveal exactly what type of explosive it was, how it was made and even how it was detonated. Critical evidence — such as fingerprints and DNA — can also be recovered from the more preserved fragments. These samples can help identify the perpetrators.
Scouring for evidence far and wide.
The most crucial evidence doesn’t just come from the fragments of the device. In fact, the entire scene will be littered with clues that will help investigators determine what has occurred and perhaps even catch those responsible.
Explosive residue, or traces of the bomb’s chemical components, provide an incredible amount of information about how an explosive was built and what materials were used in making it.
Footage captured from CCTV cameras as well as eyewitness accounts can be used to identify suspects and to reconstruct events. This is exactly what happened in 2013, following the Boston Marathon bombings.
Suspect’s houses also constitute a scene to examine as investigators may come across key evidence such as bomb making equipment and ingredients. Investigators must approach these scenes with caution — as they could be booby-trapped with further devices. In 2012, police found James Holmes’ (a shooter who killed 12 people at a movie house) apartment laden with 30 homemade grenades.
Removing the threat: preventing the time bomb.
Man’s best friend has long been trained to sniff out explosives (amongst other things). Using their heightened sense of smell — believed to be about 10,000 times stronger than a human’s — detection dogs may be able to identify even the smallest traces of explosive residue.
Mechanical scent detection, or electronic sniffer devices, are a relatively new technology that help us detect explosives. These devices capture air in a filter and run an IMS (ion-mobility spectrometry) analysis which identifies compounds by separating molecules and measuring how long they take to move through the device tube. This brilliant machine delivers the analysis results almost immediately, which saves precious time.
Luckily for King James I, he was tipped off a few days before the plot that his life was in danger. Parliament guards were on extra alert — and it’s thought that if they weren’t, Fawkes may never have been discovered. In the present day, law enforcement rely heavily on surveillance and tip-offs to stop plans to detonate explosives in their tracks as well.
Your turn: Is there anything else that we can learn from the Gunpowder Plot that may contribute to the modern forensics? Do you think this rather strange tradition should continue in modern Britain? Let us know in the comments. We’d love to hear from you.