Posts Tagged ‘forensic techniques’


4 Critical CSI Techniques Used in Terror Investigations

Wednesday, November 18th, 2015

The evening of November 13, 2015, may have begun as unremarkably as any other. By the early hours of the morning, however, a night of revelry had turned into an unconscionable tragedy — and the catastrophic loss of 129 lives.

Whilst a terrorist attack is designed to provoke panic through calculated chaos, the events that unfolded were unfortunately an echo of those that have occurred prior (and simultaneously) — by a common, real enemy.

These events engender a full-scale, comprehensive criminal investigation — especially in the event that there are suspects still at large, or insiders with prior knowledge.

Here, we recount the techniques — proven critical to gathering intelligence in the Paris attacks (November 2015) — that are used in the course of processing these scenes.

1. Severed fingers: DNA technology.

Rather remarkably, a severed finger recovered at the site of the Bataclan theatre — the seat of violence in this particular incident — led French authorities to identify the first of seven terrorists involved in the attacks.

So how does the process of identifying an attack from a mutilated body part work? Unlike a trace of bodily fluid recovered from a cleaner scene, a whole severed finger provides a copious amount of deoxyribonucleic acid, or the human body’s “blueprint” molecule. This is highly variable among a group of unrelated individuals.

The assigned technician would not, however, sequence the entirety of the genome isolated from the finger. This would be expensive, and an altogether wasteful endeavour.

DNA contains repeated sequences, with regions containing short, repeating units or STRs. For a variety of reasons — including lower mutation rates and their considerably smaller size — these shorter sequences are used to genetically differentiate people.

2. The smoking gun: ballistics testing.

The terrorists were armed with high-powered automatic weapons, thought to be Kalashnikov assault rifles. Military-class firearms, like these rifles, are prohibited across most of Europe — which raises the question: where did these individuals purchase these weapons?

The obvious answer is the black market (purchase from an illegal weapons broker) or smuggling the rifles in from abroad. Various countries in Europe have different customs regulations, which may have made it difficult to curtail the import of these weapons.

To determine precisely what firearm was fired that evening (assuming they are all the same type) — and perhaps trace the origin of this weapons to aid the investigation — ballistics analysts must examine everything from the bullet trajectory to shell casings.

Surprisingly, each type of military bullet also has a separate wound profile. By looking closely at the injuries sustained by the victims, examiners may be able to develop a more complete picture of what weapon was used.

3. Very loud noises: explosives.

The detonation of explosives outside the 80,000 capacity Stade de France was perhaps the first sign of impending danger. At this point we know that these attacks were well-coordinated: all of the suicide bombers wore nearly identical explosive devices.

The waistcoats and belts used an explosive called TATP, and contained identical batteries and push-button detonators. Triacetate tiperoxide can be produced cheaply, and using certain household ingredients.

Most likely, it took a highly-specialised and trained group of fire and explosive analysts to examine the chemical traces, or explosive residue, left behind in the debris. Samples from the surrounding areas would be tested using a variety of methods to determine precisely what compounds were utilised in the attacks.

4. Cell chatter: cybersecurity.

Digital forensics and cybersecurity — both to prevent attacks like these, and to ensure that digital infrastructure is protected — have come to the fore.

To start, an intelligence “tip-off” in this realm often begins with detection of higher “chatter” or the sheer volume of intercepted communications. However, there is evidence that the NSA has created a supercomputer (alongside its listening posts) that goes several steps farther: it looks for patterns and reveals codes in this chatter to make better sense of it.

In this case, officials in the US and Europe did pick up chatter in September about these attacks.

SOURCE: This article was first published by Forensic Outreach