This paper explores advances in forensic investigation of explosives and how application of forensics is able to aid in the development of serial bomber profiles or in linking serial bombers to scenes or scenes with other scenes. Since the topic of forensic examination of explosives could easily comprise an entire volume, the basic concepts of organized versus disorganized characteristics should hold relatively true with other serial bombing subjects.

Forensics in the Apprehension of Serial Bombers

The Chinese are largely credited with the discovery of gun powder during the Han Dynasty when Taoist alchemists who were searching for immortality mixtures composed of sulfur and potassium nitrate; by the Tang Dynasty in the late 8th century, gunpowder consisting of sulfur, potassium nitrate, and charcoal had become an implement of warfare in China (Discovery Channel, 2010). Eventually gunpowder technology was discovered in Europe through contact with Asia through either the Silk Road or through the Mongol invasion of Eastern Europe.

Gunpowder, or black powder, represents the first modern explosive operating on an oxidation reaction. Since it’s discovery explosives have been rapidly adapted as a method to kill, be it through the explosion of the cartridge of a modern firearm propelling a bullet forward from a barrel, an ANFO mixture, modern plastic explosives, or a pipe bomb (Gaensslen, Harris, & Lee, 2008). One of the more frightening aspects of explosives is they way in which they can be utilized by groups belonging within radical criminological frameworks (Schmalleger, 2009).

One of the early attempts at using explosives by a radical criminological group occurred in 1605 in England. A plot amongst radical Catholics had hatched that sought to destroy the largely Protestant Parliament as well as King James I in one fare fell swoop (, 2010). The plot called for packing over 20 barrels of gunpowder in a cellar which traveled under Parliament, and for ignition to be accomplished by Guy Fawkes who had managed to hide the 20 barrels before the first day of Parliament on November 5th, 1605 (, 2010). Fortunately, Sir Thomas Knyvet, a justice of the peace observed Fawkes acting suspiciously near the cellar and ordered the cellar searched, thereby averting a major attack from a radical group (, 2010).

While Fawkes may have been an early radical bomber, he was far from the last. Groups ranging from ethnic separatists, to Marxists, to eco terrorists have utilized explosives in furthering their ideologies (Hamm, 2004). Fortunately, the advent of modern criminological theory backed by psychology and sociology when combined with advances in forensic sciences affords modern criminal justice practitioners to apprehend bombers in ways which would make Sir Thomas Knyvet proud.

This paper in particular focuses on utilizing advances in forensic science to provide profiles of serial bombers such as George Metesky, Theodore Kacyznki, and Eric Robert Rudolph. Before exploring the scientific methods of analyzing explosives evidence, we will first consider the Federal Bureau of Investigation’s (FBI) classification system for serial offenders.

Organized versus Disorganized Profiling Methods

When profiling violent offenders, the FBI classifies them as either disorganized asocial offenders or as organized nonsocial offenders (Holmes & Holmes, 2008). The simple delineation between organized nonsocial and disorganized asocial offenders is generally the degree to which they meticulously plan and prepare for their crimes; I believe this delineation also applies to the serial bomber in both their construction and deployment of explosive devices.

If a bomb is meticulously constructed with electronic timing mechanisms and shows a degree of professionalism and is placed in an orderly fashion, we can assume the bomber is an organized nonsocial offender (Holmes & Holmes, 2008). An organized nonsocial offender is intelligent; socially and sexually competent; follows the media; can be quite charming; and has a controlled mood (Holmes & Holmes, 2008).

Contrast with a bomb created haphazardly and placed chaotically, which would indicate the bomber is likely a disorganized asocial offender (Holmes & Holmes, 2008). According to Holmes & Holmes (2008) characteristics of a disorganized asocial offender include low intelligence, social inadequacy, high anxiety during crime commission, minimal use of alcohol, live alone, are geographically limited, has little interest in news media, tends to be nocturnal, may have poor personal hygiene, has secret hiding places, does not often date, and is often a high school dropout.

Types of Explosives

Gaensslen, Harris, and Lee (2008) list 3 types of explosives: low explosives such as black powder or nitrocellulose based explosives; primary high explosives such as nitroglycerine, mercury fulminate, or lead stybnate; or secondary high explosives such as trinitrotoluene, PETN, RDX, HMX, ammonium nitrate, and urea nitrate (, 2010). Each category has it’s appeal for would be bombers as we will explore.

Low Explosive

Low explosives such as black powder, nitrocellulose, or even densely packed match heads are simple to implement in explosives. For low explosives to be effective, containment is necessary (Evans, 2004). Low explosives represent the most commonly encountered form of explosives, generally in the form of pipe bombs, like because piping is cheaply available at any hardware store and easily capped to create containment (Samuels, Boyd, & Rau, 2000). Low explosives can easily be ignited electrically or via fuse.

Primary High Explosives

Primary explosives tend to be dangerous because they are sensitive to disturbances such as shock (Gaensslen, Harris, & Lee, 2008). Primary explosives, despite their danger, do have usefulness in that they can be used as primer for cartridges or detonators for secondary explosives (Pepper, 2004).

Secondary High Explosives

Secondary high explosives are not as sensitive as primary high explosives; however, they hold a lot of the energetic properties of a primary high explosive once detonated (Gaensslen, Harris, & Lee, 2008). Unfortunately, this increased level of handling safety makes secondary explosives more difficult to detonate; therefore, a detonator consisting of a primary explosive such as mercury fulminate or lead stygnate are required (Evans, 2004). While it is quite difficult to purchase high explosives and detonators; a great deal are reported stolen to the ATF annually and can be assumed to be in the hands of criminal groups.

Forensic Methods

Understanding the different types of explosives that may be or have been present at a crime scene allows us to systematically analyze a scene to recover evidence, analyze evidence, reconstruct the scene, establish modus operandi, and compare to evidence found on a suspect or at a suspected point of manufacture. The first stage we will begin with is recovery.

Recovery & Reconstruction

There are 2 states of recovery possible, one is a scene where a device has detonated; whereas the other type of scene is one where a device was found and rendered safe. Often in the process of rendering an explosive device safe, it will be intentionally detonated by an explosives technician so it is important to understand both methods of recovery and their implications (Samuels, Boyd, & Rau, 2000). A rendered safe device that does not detonate will have components included and so does not require additional steps in recovery. An explosion on the other hand requires the collection of all components that constituted the explosive (Evans, 2004).

The first step after an explosion has occurred is the establishment of a perimeter; Evans (2004) suggests that the perimeter should be 50% larger than the assumed seat of the explosion. After a perimeter is established, the entire scene needs to be made safe, which may include shutting off utilities or disabling secondary devices (Samuels, Boyd, & Rau, 2000). After a scene is made safe, the next step is discovering the point of origin, which can typically be identified as most objects will be blown outward and away from an explosion due to the shock wave (Samuels, Boyd, & Rau, 2000). There is also the possibility that metal objects such as refrigerators and laundry machines will be warped inward when hit with a shock wave; therefore, the explosion can be assumed in the opposite direction of indentation (Evans, 2004). There is one glaring exception to objects being blown outward from the shock wave emanating from a blast, and that is flat surfaces such as counter tops and some other flat surfaces which are lifted upward as air travels over it (Evans, 2004). The physics explaining the counter tops and flat surfaces is much like an aircraft wing, both are experiencing lift because air molecules are traveling over the top faster than the bottom; therefore, it isn’t safe to assume directionality of a blast based on these types of objects.

Once investigators have determined a point of origin for an explosion, they can begin searching outward for components of the explosive such as the ignition system and other components.

Ignition system

Ignition systems can be composed of many different types of component. Low explosives such as black powder or primary high explosives such as dynamite or mercury fulminate may require nothing more than a fuse for detonation; whereas secondary high explosives will require an explosive train consisting of primary explosive in order to detonate the high explosive (Gaensslen, Harris, & Lee, 2008). An ignition system can be a stolen commercial detonator or improvised from a variety of parts and may or may not be connected to a timer or radio device. For example, a simple timer based system for a pipe bomb could have been constructed from a model rocketry igniter combined with a battery and cheap watch face. The variations are limitless and depend largely on the electronics understanding of the bomb manufacturer.

As such, it is important not to overlook seemingly insignificant components. Wires, filaments, watch parts, cell phone parts, and batteries are all examples of parts which should be collected. One way of searching for components in particularly destructive explosions is to use screens for sifting increasingly smaller debris, thereby making identification of components easier (Gaensslen, Harris, & Lee, 2008).

Explosive Residue

It is possible to collect explosive residue from scenes of explosions; Keller (2002) hypothesizes that this residue originates from the outermost layer of the explosive. Keller (2002) further offers a model which explains that the best place from which to collect residue for analysis is the seat of the explosion.

According to Hargadon and McCord (1992), capillary electrophoresis and ion chromatography are effect methods of identifying explosive residue. Further experiments conducted by Hopper, LeClair, and McCord (2005) support the use of capillary zone electrophoresis in the detection of anions and cations which provides a viable method of identifying low explosives.

Low Explosive versus Primary and Secondary Explosive

While searching for components of a probably explosive device, the existence of containment systems can be indicative that a low explosive was utilized; however, some high explosives such as ANFO also require containment for effect (, 2010, Pepper, 2004). Regardless, collection of as much containment as possible can indicate the size of the explosive, there is even the possibility that in the case of pipe bombs some explosive was left unexploded within sections of the end caps (Samuels, Boyd, & Rau, 2000).

Even if a high explosive without containment was utilized, the collection of bits of packaging is still possible; some explosives are wrapped in plastic and others may have been wrapped in paper (Gaensslen, Harris, & Lee, 2008). These portions of paper may include serial numbers, manufacture, or other indications of the explosive used and where it may have originated (Gaensslen, Harris, & Lee, 2008).

STR DNA and Other Evidence Found on the Explosive Itself

Once components are collected, it is still possible to collect evidence from the components themselves. For example, it is possible to find a fingerprint on a battery or a hair trapped in the threads of a pipe cap (Pepper, 2004). The most interesting recent research indicates the viability of collecting epithelial evidence which can be DNA typed using STR DNA. Studies conducted by Esslinger, Siegel, Spillane, and Stallworth (2004) show that in at least one out of five instances in which a suspect handles a pipe bomb which is subsequently exploded, reliable epithelial evidence can be retrieved.

Evidence Found on the Suspect

The work of Ahmad, Hassan, and Rajendran (2008) showed that individuals who have handled explosives can be detected by taking hand swabs. Recovery rate for Ahmad, Hassan, and Rajendran (2008) was nearly 90% when swabs taken of Malaysian servicemen who had handled PETN were subjected to high performance liquid chromatography with an ultraviolet detector.

Given the ability of explosives residue to transfer, Pepper (2004) highly recommends that steps be taken to reduce the possibility of accidentally cross contaminating scenes and suspects. He recommends that a single crime scene investigators should never test both the suspect and the scene; that investigators should always wear full protective clothing including oversuit, gloves, and overshoes; only new equipment should be used; vehicles, and especially tires should be thoroughly cleaned; and that investigators should shower thoroughly after examining the scene (Pepper, 2004).

Evidence Found at the Point of Manufacture

Cross contamination is also a concern when searching a suspected point of manufacture; however, there are many more types of evidence which can be collected at a point of manufacture. Generally, items that would be used in the construction of an explosive device are important to be seized, this includes wires, batteries, model rocketry components, soldering equipment, electric matches, fuses, as well as any high and low explosives amongst other potential components. Of particular interest at a point of manufacture are the seizure of tools used in the manufacture of explosive devices as these tools may have left striations in the form of tool marks on the explosive found at the crime scene (Gaensslen, Harris, & Lee, 2008). A firearms and tool mark examiner can match markings made on the explosive to those known to have been created by tools found at the suspected point of manufacture (Gaensslen, Harris, & Lee, 2008).

Establishing a Profile

Modus operandi is the Latin term for a method of operation, specifically in relation to criminal behavior (Schmalleger, 2009). As people are creatures of habit, when they discover a method of doing something that works it is very difficult for them to change out of a working habit (Gaensslen, Harris, & Lee, 2008). This allows investigators to make the assumption that a serial bomber will continue to utilize the same methods of explosive device construction.

When observing the components which were used to construct an explosive device, it is possible to determine the typology of the maker. For example, if a bomber leaves a simple pipe bomb in a crowd, he is likely a disorganized asocial type. The more advanced the electronics and explosive train the more likely the bomber is an organized nonsocial type.

Case Studies

To exemplify typologies of serial bomber we will examine what I would classify as an organized nonsocial type and a disorganized asocial type. These case studies were selected as a convenience sample based on articles and research already available from interviews and police. While numerically this sample is far too small to be definitive, they are still reliable for illustrative purposes.

Theodore Kacyznksi

Theodore “Ted” Kacynski was a quiet yet incredibly bright individual who went so far as to receive a PhD in mathematics and went on to serve as an assistant professor at the University of California at Berkeley (Schmalleger, 2009). Kacyznski went on to denounce aspects of modernity, leaving his professorship for a life of solidarity in Montana (Gaensslen, Harris, & Lee, 2008). Kacyznski in his radical ideologies began sending explosive packages to university professors; between the years 1978 and 1995 Kacyznski created over 16 pipe bombs which were utilized in attacks (Schmalleger, 2009). Kacyznski was meticulous in creating his explosives, even going so far as to create hand crafted wooden boxes which housed pipes that were uniquely capped using pins rather than the end caps being threaded; all of this work and experimentation with explosives was even carefully recorded by Kacyznski via notation (Schmalleger, 2009).

Kacyznski personifies the organized nonsocial serial bomber; he was smart, controlled his mood, and followed the media closely. His personality was expressed in the types of explosives he fashioned. When Kacyznski was eventually apprehended, his point of manufacture for his explosives offered a wealth of forensic evidence including components and a fully functional explosive device with characteristics matching those of previous explosives from Kacyznski (Schmalleger).

Eric Robert Rudolph

Eric Robert Rudolph is an interesting figure in serial bombing profiling history because one of his explosives, an explosive which detonated in the Olympic park during the 1996 Atlanta Olympics, was controversially profiled and attributed to the wrong individual (Holmes & Holmes, 2008). Eric Robert Rudolph was described as below average intelligence and dropped out of high school (Fonda, Cuardos, Fulton, Landa, Richards-Murphy, & Sikora, 2003). Furthermore, a home Rudolph prior to the Atlanta bombings included an underground hiding place that Rudolph called “the root cellar” (Fonda, Cuardos, Fulton, Landa, Richards-Murphy, & Sikora, 2003).

Rudolph, who can best be described as a radical Christian domestic terrorist, preferred to use nails for shrapnel in his explosive devices which targeted the 1996 Olympics, abortion clinics, and homosexual clubs; reported injuries list more than 120 people being injured by Rudolph’s explosives (Fonda, Cuardos, Fulton, Landa, Richards-Murphy, & Sikora, 2003). Futhermore Rudolph’s devices were not as intricate or methodological as other serial bombers such as Kaczynski; combined these aspects would classify Rudolph as a disorganized asocial serial bomber.

Conclusion and Implications

With the establishment that advances in forensics has substantially increased the ability of law enforcement to link individuals to explosives and explosives to other similar explosives, and the further establishment that forensic advancements are continuing to improve the ability of law enforcement to profile serial bombers, the only remaining aspect to making this information useful is nation wide data warehousing of explosives information. Fortunately, the ATF provides access to the Bomb and Arson Tracking System (BATS) which provides arson and explosives investigators with the ability to form linkages between scenes and individuals (ATF, 2010).

Due to their longstanding reputation as an effective destructive implement and ease of manufacture or acquisition, there is little doubt that explosives will continue to be present in the hands of individuals and groups classified within the radical criminological schools. Continuing advancements in forensic examination of explosives will continue to play a pivotal role in apprehending serial bombers.


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