Detection of Homemade Bombs in Forensic Investigations
Homemade bombs(HMBs) are a type of unconventional explosive that can be deployed anywhere in a variety of ways and can cause death, injury, and property damage.
The homemade bomb consists of a variety of components which include an initiator, switch, main charge, power source, and containers. To increase the number of casualties of the explosion, the bomb makers will include additional materials such as nail, glass, metal fragments. Other materials may also contain other elements such as hazardous materials. The homemade bomb can be detonated by a variety of methods depending on the intended target and the place of deployment.
Homemade Explosives Information Sources
- All the information and reference for the construction and deployment of Homemade bombs are widely available to the public by different sources.
- Different methods of explosives attacks and their assembly are described in detail in the Al-Qaida’s and Jihad’s training manuals.
- Several books and research publishers publish books and articles that show how to build using improvised materials and commercial products.
- Military field manuals have also been used as a source of information and can be purchased at the doorstep online.
- All information regarding the construction of HMBs is also easily found on the internet and is readily available to anyone with internet access.
Explosives Used in Homemade Bombs
Commonly available materials are mainly used in HMBs such as fertilizers, gunpowder, and hydrogen peroxide. The bomb should contain fuel and an oxidizer, which provides the oxygen needed to sustain the reaction. ANFO, a mixture of ammonium nitrate, which acts as the oxidizer, and the fuel oil is a common example of these types of explosives.
Many of the substances for making an explosive simply require very little technical knowledge or specialized equipment. Instructions on how to make them are provided online and in written resources. Sometimes the recipes for homemade bombs are often inaccurate and dangerous to follow and some explosive materials are created often highly unstable.
Identification of Homemade Bombs
- Unusual packages or containers with electronic components, such as cellular phone, antenna, circuit board, wires, and other items attached or exposed.
- Any devices containing quantities of fireworks, black powder, fuses, match heads, incendiary materials, smokeless powder, and other unusual materials are considered suspicious.
- Containers like pipes with wire circuits, pressure cookers, etc in public places should be considered as unusual devices.
- Materials attached to an item such as a bolt, nails, pin, glass, marble pieces, and so on that could be used for shrapnel.
- Use of portable X-ray tool to examine suspicious baggage/package to determine the presence of any explosive materials.
- DRDO and IIS recently developed a new bomb detection apparatus called Raider-X. 20 homemade bomb explosives from up to 20 meters away can be easily detected. Raider-X data library can be updated to accommodate the new details of different explosives in pure and in their contaminated form.
Forensic Analysis of Homemade Bombs Explosives
- Forensic analysis of homemade explosives materials is critical for determining the origin of explosives, precursors, and formulation procedures.
- Extra care should be taken during collection, preservation, and analysis of the pre/post explosive materials.
- A database (with specified confidence levels) of mass, thermal, infrared spectral signature, and isotopic composition and ratios of correlated pre-identified homemade explosives precursors.
- Gas chromatography is frequently used for the identification of organic explosive components in the bomb. The technique has high sensitivity and selectivity towards organic constituent in the residue. The detector used is combined with GC is thermal energy analyzer (TEA), electron capture detection (ECD), mass spectrometry (MS), and tandem mass spectrometry (MS/MS).
- High-performance liquid chromatography (HPLC) is used for the detection of organic compounds that are non-volatile in nature. It is often used as the instrument for the analysis of explosive as it is amenable for the analysis of compound that has low volatility, high sensitivity to heat, and high molecular weight.
- Ultra- HPLC has recently widely used among researchers because of its effectiveness for compound separation and its sensitivity.
- Capillary electrophoresis (CE) is used for the analysis of inorganic compounds in the residue. In CE, targeted analytes elute from one end of the capillary under the influence of the electric field, and analytes are separated according to their ionic mobility and this method is successfully used to determine 3 cations (Ca2+, Fe2+, Fe3+) and 4 anions (Cl-, NO32-, SO42-, SCN-) simultaneously under 7 minutes at pH 4.7. Post blast explosive residues of black powder and ammonium nitrate-fuel oil (ANFO) can also be successfully analyzed through this technique.
- X-ray powder diffraction (XRD) and X-ray fluorescence are non- destructive techniques. It is used for the composition analysis of crystalline material in the explosive. Both of the techniques are different but complementary to each other whereby XRD used to analyze the phases or compounds in it meanwhile XRF is utilized for the analysis of the elemental composition of crystalline material.
Examples of Terrorist Homemade Bombs Attacks
Boston Marathon bombing
A homemade bomb attack happened in Boston during the annual Boston Marathon on April 15, 2013. Two homemade pressure-cooker bombs detonated within 8-14 seconds and 210 yards (190m) apart at 2:49 pm near the finishing line of the marathon run. This blast killing 3 people and injuring several hundred others, including 17 who lost limbs.
Madrid Train Attacks
10 explosions rocked through 4 commuter trains during rush hour on March 11, 2004, in Madrid, Spain. Goma 2 ECO explosives were stuffed in bags with metals fragments, cell phones with timers that are used to initiate the explosive device. This attack was carried out by violent Islamic extremists, killed 191 people, and injured more than 1800.
Oklahoma City Bombing
On the morning of April 19, 1995, a truck bomb exploded in front of the Federal Building in Oklahoma City. Ammonium nitrate and nitromethane are used in the explosion which was put into the back of the truck and left to explode.
‘By Vimal KB’
Vimal completed his graduation in B.Sc. Forensic Science from Galgotias University and is currently pursuing MSc Forensic Science from CTM IRTE, Faridabad. He did his internship at Kerala Police Academy, Thrissur.