Criminal Investigations: Fires and Explosives

The forensic sciences have benefited greatly from innovations in computer technologies and even decades-old cold case crimes are now being routinely solved as a result. In particular, computer fire models have become increasingly sophisticated in their ability to identify the source, causes and timing of fires. Likewise, forensic investigations of terrorist uses of improvised explosive devices (IEDs) have benefited from a growing body of knowledge concerning their design, construction and deployment as well as the fragmentation of pipe bombs with varying case thicknesses. To determine their status of these forensic methods, the purpose of this paper is to provide a discussion concerning the evolution of fire investigations and their impact on arson cases and the reliability of computer fire models at trial. In addition, an overview of terrorist use of IEDs and what is known about the fragmentation of pipe bombs with varying case thicknesses is followed by a summary of the research and important findings concerning these forensic methods in the conclusion.

The evolution of fire investigations and its impact on arson cases and the reliability of computer fire models at trial

The evolution of fire investigations over the past 30 years or so has changed the nature of the enterprise from one in which suppositions and long-held beliefs by investigators has been replaced with a model that emphasizes scientific analyses (Lentini, 2012). Moreover, in the past, the majority of fire investigators received no formal training and relied instead on the belief systems of superiors and their empirical observations based on their individual experiences in investigating fires (Lentini, 2012, p. 37). Although significant progress has been made in modernizing fire investigations, the profession is still marred by a lack of needed funding to ensure that practitioners possess the skill set that is needed to perform scientific fire investigations and to allow them to keep pace with new developments in the field (Lentini, 2012).

Notwithstanding these constraints, the United States has succeeded in developing national standards for the professional qualifications for both public and private fire investigators. Besides remaining current with new developments in the field and pursuing continuing education as in other professional fields, the National Fire Protection Associations certification as a professional fire investigator now requires a minimum of current knowledge at an advanced educational level for the following:

(1) Fire science;

(2) Fire chemistry;

(3) Thermodynamics;

(4) Thermometry;

(5) Fire dynamics;

(6) Explosion dynamics;

(7) Computer fire modeling;

(8) Fire investigation;

(9) Fire analysis;

(10) Fire investigation methodology;

(11) Fire investigation technology;

(12) Hazardous materials; and

(13) Failure analysis and analytical tools (Lentini, 2012, p. 48).

Taken together, it is clear that modern fire investigations draw on a wide range of disciplines, fields and sciences that reflect their ongoing evolution. In addition, fire investigators today can also benefit from education and training in the primary motivators for criminally set fires which can help them determine the cause of fires but whether it was intentionally set in the first place. For instance, according to Pavlisin et al. (2009), fire investigators for insurance companies now search for any evidence of criminal intent during their initial investigations which can help identify the arsonist. In this regard, Pavlisin et al. (2009) report that, The initial fire investigation may yield one or more red flags that require the insured to be ruled out as having intentionally set...…death (as cited in Walsh, 2021).

While explosive-laden vehicles have also been used in recent years (Drozl et al., 2018), pipe bombs remain the most popular types of IEDs used by terrorist organizations today (da Silva et al., 2020). In this regard, da Silva et al. (2020) emphasize that, Among all the improvised explosive devices 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 (p. 306). Because fragmentation of pipe bomb cases represents the main mechanism for inflicting human casualties, the thicknesses of the pipes that are used has a direct effect on their lethality (de Silva et al., 2020). While additional research is needed, the studies to date confirm a direct correlation between case thickness and the size and velocity of detonated pipe bomb fragments (da Silva et al., 2020).

Conclusion

The research showed that the evolution of fire investigations over the past 3 decades has been characterized by the increasing sophistication of investigatory methods that draw on a wide range of scientific disciplines. The development of national standards for professional certification for fire investigators and computer-assisted methods have accelerated this process, but the research was also consistent in showing that these individuals require additional resources to develop and maintain the skills set that is required for modern fire investigations. Although computer fire modeling is among this skill set, these types of findings are still not admissible at trial as evidence. Finally, the research was also consistent in showing that asymmetrical warfare strategies that use improved explosive devices such as pipe bombs by terrorist organizations remains a threat at home and…