Pipe Bombs Research Articles

Forensic Analysis of Recrystallized Inorganic Oxidizing Salts Used in Pyrotechnic-Based Improvised Explosive Devices Using Light Microscopy and Micro-Raman Spectroscopy

This study aimed to evaluate the advantages and challenges of analyzing post-blast pyrotechnic pipe bombs using a combination of light microscopy and micro-Raman spectroscopy. Two simulated improvised explosive devices (IEDs) were constructed and exploded using pyrotechnics as the main charge and consisted of several different components to simulate common materials that might be found in authentic bombing scenarios. In order to develop a rapid explosives residue recovery technique, a wet and dry swabbing process was compared to determine the most efficient swabbing method of recovery for inorganic oxidizers in post-blast debris. Samples were recrystallized using a water recrystallization method followed by in situ analysis using polarized light microscopy (PLM) and micro-Raman spectroscopy, targeting euhedral and subhedral crystals. While the water recrystallization had effects on the resulting Raman spectrum, such as peak intensity reduction, ultimately, the final salt identifications were not affected. The detection of several inorganic oxidizers post-blast included the identification of potassium perchlorate (KClO4), potassium nitrate (KNO3), and barium nitrate (Ba(NO3)2). The detection of KNO3 using microscopy alone was more challenging due to its relatively low abundance compared to KClO4 but was achieved with micro-Raman spectroscopy. Additionally, the mixing of inorganic oxidizers within single crystals was also observed. The results indicated that the combined approach of microscopy and micro-Raman spectroscopy enabled the successful detection of inorganic oxidizing salts in a post-blast scenario, as well as describing the advantages and limitations of this combination of techniques.

Characterization and comparison of smokeless powders by on-line two-dimensional liquid chromatography

Smokeless powders (SPs) are one of the most commonly used propellants for ammunition but can also be abused as energetic material in improvised explosive devices (IEDs) such as pipe bombs. After a shooting or explosion, unburnt or partially burnt particulates may be observed which can be used for forensic investigation. SPs comprise mainly nitrocellulose (NC) and additives. Therefore, the characterization of both NC and the additives is of significant forensic importance. Typically, the identification, classification, and chemical profiling of smokeless powders are based exclusively on the analysis of the additives. In this study, information regarding the NC base component was combined with the chemical analysis of the additives using two-dimensional liquid chromatography (2D-LC). The system combines size-exclusion chromatography (SEC) and reversed-phase liquid chromatography (RPLC) in an on-line heart-cut 2D-LC configuration. In the first dimension, the NC is characterized by its molecular-weight distribution (MWD) while being separated from the additives. The additives are then transferred to the second-dimension separation using a novel analyte-transfer system. In the second dimension, the additives are separated to obtain a detailed profile of the low-molecular-mass compounds in the SP. With this approach, the MWD of the NC and the composition of the additives in SP have been obtained within an hour. A discrimination power of 90.53% was obtained when studying exclusively the NC MWD, and 99.47% for the additive profile. This novel combination enables detailed forensic comparison of intact SPs. Additionally, no extensive sample preparation is required, making the developed method less labor intensive.

Quantitative analysis of smokeless powder particles in post-blast debris via gas chromatography/vacuum ultraviolet spectroscopy (GC/VUV).

Forensic analysis of smokeless powder particles recovered from the debris of an improvised explosive device can provide information about the type of smokeless powder used and can aid investigation efforts. In this study, quantitative methods were used to yield information about the difference in the chemical composition of the particles pre‐ and post‐blast. The technique, gas chromatography/vacuum ultraviolet spectroscopy (GC/VUV), was able to quantify nitroglycerin, 2,4‐dinitrotoluene, diphenylamine, ethyl centralite, and di‐n‐butyl phthalate in pre‐ and post‐blast smokeless powder particles using heptadecane as an internal standard. Post‐blast debris was obtained via controlled explosions with assistance from the Indiana State Police Bomb Squad. Two galvanized steel and two polyvinyl chloride pipe bombs were assembled. Two devices contained single‐base smokeless powder and two contained double‐base smokeless powder. 2,4‐dinitrotoluene and diphenylamine were successfully quantified in the single‐base smokeless powder post‐blast debris while nitroglycerin, diphenylamine, and ethyl centralite were successfully quantified in the double‐base smokeless powder post‐blast debris. Compounds were detected at concentrations as low as 9 μg of 2,4‐dinitrotoluene per mg, <3 μg of diphenylamine per mg, 131 μg of nitroglycerin per mg, and <3 μg of ethyl centralite per mg. Concentration changes between pre‐ and post‐blast smokeless powder particles were determined as well as microscopic differences between pre‐ and post‐blast debris for both smokeless powders in all devices. To our knowledge, this is the first use of GC/VUV for the quantification of explosives.

Postmortem CT and autopsy findings in nine victims of terrorist attack.

In a foreign country, a religious terrorist group raided a restaurant, using pipe bombs, sharp-edged weapons, and various types of firearms (handguns, submachine guns, and AK-47 assault rifles) loaded with normal and prohibited bullets to kill foreigner customers, some of whom were Italian tourists. Local pathologists performed forensic autopsies on the bodies, but we were asked to perform additional external examinations, postmortem computed tomography (PMCT) scans, and then a second round of complete autopsies on nine victims (5 females and 4 males). Four victims had slash wounds inflicted by sharp-edged weapons, mostly localized in the head and neck. All but two victims had gunshot wounds. Finally, three casualties had injuries caused by the explosion of improvised explosive devices. In all cases, PMCT was a reliable source of information and provided strategic guide during autopsies, helping identify and describe the injuries and thus reconstruct the events. Therefore, in these cases, we suggest integrating the autopsy findings with the postmortem radiological data.

Fragmentation studies by non-explosive cylinder expansion technique

Expansion and fragmentation of metallic cylinders is an important area of study both for designing munitions and mitigation techniques against fragments as well as in the failure of pressurised pipes in industry. Most of the reported studies on fragmentation have been carried out by detonating explosively filled metallic cylinders. However, this approach has inherent limitations in terms of both safety and repeatability – not least due to packing issues with explosive fills. Fragmentation studies on hollow metallic cylinders of both mild and stainless steel of various thicknesses (2–4 mm) were carried out by firing a polycarbonate projectile from a single-stage light gas gun. Strain rates of the order of 2 × 104 s−1 were observed at cylinder expansion velocities of 400–450 m s−1, calculated from flash X-ray radiographs. The differences in fragmentation behaviour of both materials was observed, attributed to their different response to high strain-rate loadings.Microscopic analysis of mild steel fragments showed interesting alignment of ferrite and pearlite grains, similar to reported effects of explosive loading. This suggests the potential to employ this technique to simulate explosive cylinder expansion in a non-explosive laboratory environment enabling a convenient recovery of fragments. Numerical modelling with using ANSYS AUTODYN® allowed for a better understanding of the various parameters controlling expansion and fragmentation. Analysis of recovered fragments by a Fragment Weight Distribution Map (FWDM), a method generally used for characterising pipe bombs, could clearly demonstrate the effect of casing material and thickness.

Experimental fragmentation of pipe bombs with varying case thickness

Among all the improvised explosive devices (IEDs) known, pipe bombs are one of the most popular devices used by terrorists. They are simple to use, easy to construct and materials are readily available. For this IED, fragmentation is the primary injury mechanism, which makes them a desirable weapon for terrorists aiming to inflict maximum human casualties. Although the investigation of fragmentation pattern is not novel, there is limited data available on pipe bombs performance in the open literature. Therefore, this research is looking at validating results in current literature, which showed limited repetition and weak experimental design so far; by trial with six pipe bombs with two different thickness (3 of each). The pipe bombs consisted of mild steel casing and aluminised ammonium nitrate as the explosive filler. Fragments were collected, with an average recovery of 72%, and measured regarding mass and velocity. The experiment results show a correlation between the pipe thickness and both the size and velocity of fragments.

Collection and direct amplification methods using the GlobalFiler™ kit for DNA recovered from common pipe bomb substrates

When analyzing DNA from exploded pipe bombs, quantities are often in trace amounts, making DNA typing extremely difficult. Amplifying minute amounts of DNA can cause stochastic effects resulting in partial or uninterpretable profiles. Therefore, the initial DNA collection from “touch” evidence must be optimized to maximize the amount of DNA available for analysis.This proof-of-concept study evaluated two different swab types with two direct amplification strategies to identify the most effective method for recovering DNA from common pipe bomb substrates. PVC and steel pipes, electrical tape, and copper wire spiked with epithelial cells were swabbed with cotton or microFLOQ® Direct Swabs and amplified directly or via a pre-treatment prior to STR amplification.Not only was the microFLOQ® Direct Swab protocol the quickest method with the least risk of contamination, but in combination with direct amplification, the microFLOQ® Direct Swabs also generated the most complete STR profiles.

Post-blast detection of human DNA on improvised explosive device fragments

ABSTRACTMany terrorist attacks employ the use of improvised explosive devices such as pipe bombs. In these circumstances, the perpetrator may be absent from the scene, necessitating the need for a quick resolution. Forensic DNA analysis is one of the key disciplines utilized to identify possible offenders in terror-related crimes; however, its success in post-blast environments is unpredictable. Through using a known quantity of human DNA on pre-blast samples, post-blast DNA results can be assessed for STR profiling suitability. In this study, two pipe bombs were constructed and doped with varying concentrations of human blood. The samples were extracted using the DNA IQ System extraction kit and quantified using the Quantifiler Trio DNA Quantification Kit. The results obtained from this analysis confirm the presence of DNA post-blast. The variation between post-blast and pre-blast samples was not found to be statistically significantly different. Furthermore, the results indicate that 55% of the samples quantified post-blast could produce partial or full profiles in downstream DNA testing.

Floris White Bull Responds to the Editors on Protest and the Film &lt;em&gt;AWAKE: A Dream from Standing Rock&lt;/em&gt;

Floris White Bull Responds to the Editors on Protest and the Film &lt;em&gt;AWAKE: A Dream from Standing Rock&lt;/em&gt;

Characterizing the Performance of Pipe Bombs.

Pipe bombs of steel or PVC fragment in reproducible patterns when similarly configured. The power of the explosion correlates with number, mass, and size of the fragments recovered, where a large number of small, low-mass fragments indicate a high-power event and vice versa. In discussing performance, describing pipe fragmentation pattern by fragment weight distribution mapping (FWDM) or fragment surface area distribution mapping (FSADM) was useful. When fillers detonated, detonation velocities of ~4.4 mm/μs were measured. In such cases, side walls of the pipe were thrown first; the average fragment velocity was ~1000 km/s. In deflagrations, the end cap was first thrown; fragment velocities were only ~240 km/s. Blast overpressures varied; at 10 feet, 2 × 12 inch steel pipes containing ~550 g of detonable mixture produced overpressures of 5-6 psi; similar nondetonating pipes produced less than 2 psi. Maximum fragment throw distances were 250-300 m, with an average of ~100 m.

Analysis of DNA from post-blast pipe bomb fragments for identification and determination of ancestry

Improvised explosive devices (IEDs) such as pipe bombs are weapons used to detrimentally affect people and communities. A readily accessible brand of exploding targets called Tannerite® has been identified as a potential material for abuse as an explosive in pipe bombs. The ability to recover and genotype DNA from such weapons may be vital in the effort to identify suspects associated with these devices. While it is possible to recover DNA from post-blast fragments using short tandem repeat markers (STRs), genotyping success can be negatively affected by low quantities of DNA, degradation, and/or PCR inhibitors. Alternative markers such as insertion/null (INNULs) and single nucleotide polymorphisms (SNPs) are bi-allelic genetic markers that are shorter genomic targets than STRs for amplification, which are more likely to resist degradation.In this study, we constructed pipe bombs that were spiked with known amounts of biological material to: 1) recover "touch" DNA from the surface of the device, and 2) recover traces of blood from the ends of wires (simulated finger prick). The bombs were detonated with the binary explosive Tannerite® using double-base smokeless powder to initiate the reaction.DNA extracted from the post-blast fragments was quantified with the Quantifiler® Trio DNA Quantification Kit. STR analysis was conducted using the GlobalFiler® Amplification Kit, INNULs were amplified using an early-access version of the InnoTyper™ 21 Kit, and SNP analysis via massively parallel sequencing (MPS) was performed using the HID-Ion Ampliseq™ Identity and Ancestry panels using the Ion Chef and Ion PGM sequencing system.The results of this study showed that INNUL markers resulted in the most complete genetic profiles when compared to STR and SNP profiles. The random match probabilities calculated for samples using INNULs were lower than with STRs when less than 14 STR alleles were reported. These results suggest that INNUL analysis may be well suited for low-template and/or degraded DNA samples, and may be used to supplement incomplete or failed STR analysis. Human identification using SNP analysis via MPS showed variable success with low-level post-blast samples in this study (<150pg). While neat DNA samples (6μL input as recommended) resulted in <50% of SNP calls, samples that were concentrated from 15μL to 6μL (15μL was added for STR and INNUL typing) resulted in more complete SNP profiles. Five out of six blood samples recovered from the wires attached to the pipe-bombs resulted in the correct ancestry predictions.

Mapping explosive residues on galvanized pipe bomb fragments using total vaporization solid phase microextraction (TV-SPME)

Total Vaporization Solid Phase Microextraction (TV-SPME) can quantitate trace explosive residues on post-blast debris.

Determination of anionic profiling of improvised explosive devices from different types of low explosive material

Improvised explosive devices or also known as homemade explosive devices are frequently abused for public terrorism. This types of explosive devices are well fabricated and made in improvised manner by incorporating military or commercially sourced explosive. It is often used for terrorism as the material of the devices are readily available at low cost and can be obtain legally without any suspicion from the sellers. Chemical composition of explosives holds a lot of useful information in establishing a link between a perpetrator and a bombing case. Analysis of post-blast explosive and pre-blast explosive is equally important since the chemical reaction during explosion will change the product of the composition. Different types of explosive material are also expected to give different composition profiling. In this study, four types of pyrotechnics explosives packed in pipe bombs were utilized via sampling exercise. Cotton swabbing technique was employed as method extraction as it is easy to perform, rapid, less solvent use and lab time are reduced.The determination of anionic inorganic constituents of improvised explosives were performed using ion chromatography. Post blast residues were analyzed to compare the changes of inorganic ions to its origin from pre blast samples. Inorganic ions were separated using Metrosep A SUPP 5 column and an eluent consisting of 1.0 mmol/L of NaHCO3 with 3.2 mmol/L Na2CO3. Anions of interest including NO2-, NO32-, PO42-, SO42-, SCN-, and ClO4- have been successfully separated within 60 minutes. Types and amount of anion detected are different from different materials of explosive devices.________________________________________GRAPHICAL ABSTRACT

The anatomy of a pipe bomb explosion: The effect of explosive filler, container material and ambient temperature on device fragmentation

Understanding the mechanical properties of different piping material under various conditions is important to predicting the behavior of pipe bombs. In this study, the effect of temperature on pipe bomb containers (i.e., PVC, black steel and galvanized steel) containing low explosive fillers (i.e., Pyrodex and double-base smokeless powder (DBSP)) was investigated. Measurements of fragment velocity and mass were compared for similar devices exploded in the spring (low/high temperature was 8°C/21°C) and winter (low/high temperature range was −9°C/−3°C). The explosions were captured using high speed filmography and fragment velocities were plotted as particle vector velocity maps (PVVM). The time that elapsed between the initiation of the winter devices containing double-base smokeless powder (DBSP) and the failure of their pipe containers ranged from 5.4 to 8.1ms. The maximum fragment velocities for these devices ranged from 332 to 567m/s. The steel devices ruptured and exploded more quickly than the PVC device. The steel devices also generated fragments with higher top speeds. Distributions of fragment masses were plotted as histograms and fragment weight distribution maps (FWDM). As expected, steel devices generated fewer, larger fragments than did the PVC devices. Comparison to devices exploded in the spring revealed several pieces of evidence for temperature effects on pipe bombs. For example, the mean fragment velocities for the winter devices were at or above those observed in the spring. The maximum fragment velocity was also higher for the winter steel devices. Although there were no significant differences in mean relative fragment mass, the fragment weight distribution maps (FWDMs) for two winter devices had anomalous slopes, where lower energy filler caused more severe fragmentation than higher energy filler.

The Anatomy of a Pipe Bomb Explosion: Measuring the Mass and Velocity Distributions of Container Fragments

Improvised explosive devices such as pipe bombs are prevalent due to the availability of materials and ease of construction. However, little is known about how these devices actually explode, as few attempts to characterize fragmentation patterns have been attempted. In this study, seven devices composed of various pipe materials (PVC, black steel, and galvanized steel) and two energetic fillers (Pyrodex and Alliant Red Dot) were initiated and the explosions captured using high-speed videography. The video footage was used to calculate fragment velocities, which were represented as particle velocity vector maps. In addition, the fragments were weighed. The results demonstrate a correlation between the type of energetic filler and both the size and velocity of the fragments. Larger fragments were produced by Pyrodex filler indicating a less complete fragmentation, compared with smaller fragments produced by double-base smokeless powder. Additionally, higher fragment velocities were seen with Alliant Red Dot filler.

Physical Characterization and Recovery of Corroded Fingerprint Impressions from Postblast Copper Pipe Bomb Fragments

Pipe bombs made from 1mm thick copper pipe were detonated with a low explosive power powder. Analysis of the physical characteristics of fragments revealed that the copper had undergone work hardening with an increased Vickers Hardness of 107HV1 compared with 80HV1 for unexploded copper pipe. Mean plastic strain prior to fracture was calculated at 0.28 showing evidence of both plastic deformation and wall thinning. An examination of the external surface showed microfractures running parallel with the length of the pipe at approximately 100μm intervals and 1-2μm in width. Many larger fragments had folded "inside out" making the original outside surface inaccessible and difficult to fold back through work hardening. A visual examination for fingerprint corrosion revealed ridge details on several fragments that were enhanced by selective digital mapping of colors reflected from the surface of the copper. One of these fingerprints was identified partially to the original donor.

Investigative Studies into the Recovery of DNA from Improvised Explosive Device Containers*,‡

Apprehending those who utilize improvised explosive devices (IEDs) is a national priority owing to their use both domestically and abroad. IEDs are often concealed in bags, boxes, or backpacks to prevent their detection. Given this, the goal of the research presented was to identify IED handlers through postblast DNA recovery from IED containers. Study participants were asked to use backpacks for 11 days, after which they served as containers for pipe bombs. Eleven postdeflagration backpack regions likely to be handled were swabbed and analyzed via mini-short tandem repeats (miniSTRs) and alleles were called blind. An experimental consensus method was examined in which profiles from all regions were considered, to help identify spurious drop-in/out. Results were correct for all loci, except one that remained ambiguous. The results show that recovering DNA from IED containers is a viable approach for aiding in the identification of those who may have been involved in an IED event.

The recovery of DNA profiles from saliva and touch evidences after postal bomb explosion

Terrorist crime usually makes use of improvised explosive disposals (IEDs) which, especially in national environments, consist of postal or pipe bombs often assembled by using plastic or paper envelopes, adhesive tapes, electric components such as switches, batteries, cables, etc. To date it has been considering quite complex to recover DNA in quality and quantity proper for STRs typing aimed at the identification of the manufacturer of the IED especially due to the very serious damage degree of the evidence (exposed to high temperatures). In this work we tested saliva and touch evidences (perspiration), usually found on a postal package, deposed inside the postal bombs charged with deflagrating or detonating explosives in different quantities and we evaluated the possibility to achieve DNA profiles useable for identification purposes from such kind of post-explosion biological evidences. We demonstrated that with new generation multiplexes it is possible to gain STRs profile useful for identification purposes even from highly burned and degraded bomb debris.

Development of Alternative Projectile to Deactivate an Improvised Explosive Device - Pipe Bomb

The article describes a possibility of dealing with the problem represented by an improvised explosive device in the form of a pipe bomb so that the problem may be solved quickly and reliably, i.e. so that the pipe bomb may be deactivated without explosion. The article describes the development of an alternative projectile that will replace the water content in the water gun; thus it will make it possible to remove metallic end caps closing pipe bombs so that the bombs can be disassembled without explosion, and subsequently to subject the dismantled parts to forensic examination to detect a designer of the improvised pipe bomb.

Discriminating Hodgdon Pyrodex® and Triple Seven® Using Gas Chromatography-Mass Spectrometry

Pyrodex(®) and Triple Seven(®) are black powder substitutes that often find use as fillers in improvised explosive devices, such as pipe bombs. These propellants have essentially the same overall appearance and oxidizers, but different fuels. For example, Pyrodex(®) contains sulfur, sodium benzoate, and dicyandiamide (DCDA), whereas Triple Seven(®) lacks sulfur but also contains 3-nitrobenzoic acid. In this method, intact particles and postblast solid residues were reacted with bis(trimethylsilyl)trifluoroacetamide + 1% trimethylchlorosilane in acetonitrile for 30 min at 60°C. The resultant trimethylsilyl derivatives of the organic fuels were then analyzed by gas chromatography-mass spectrometry. Each derivative was clearly resolved from other components, and high-quality mass spectra were obtained. In addition, characteristic fragments resulting from loss of a methyl radical from the molecular ion (m/z 163 for sulfur, m/z 171 for DCDA, m/z 179 for benzoic acid, and m/z 224 for nitrobenzoic acid) were able to be monitored.