Other than investigating fire cause, what are the functions of the arson unit

110 Definition of Arson

Arson by definition is the willful and malicious setting fire to, or causing to be burned, or aiding, counseling or procuring the burning of, a dwelling house, or building adjoining or adjacent to a dwelling house, or a building by the burning whereof a dwelling house is burned, whether such dwelling house or other building is the property of himself or another and whether the same is occupied or unoccupied.7

The Role of Law Enforcement Instructors

To further understand how the discipline of bloodstain pattern interpretation has evolved, we need to look at the instructors of bloodstain pattern courses and their students. Many of the instructors that hold weeklong basic schools in bloodstain pattern interpretation are active or retired police officers. Their students are mostly police officers whose duties included crime scene investigation. Police officers instructing police officers is a desirable thing unless the training officer is not qualified or some of the material being taught is not accurate or is incomplete. When an instructing officer is inaccurate, instead of one individual officer misinterpreting bloodstain patterns, a class full of officers is trained to make the same mistakes.

Officers training officers is also questionable because the subject, when treated properly, requires a deep understanding of scientific principles, the use of experimentation, and the scientific method, and the application of biology, physics, and mathematics. For bloodstain pattern analysis to function as an objective science, and to move it from the list of subjective pseudo-sciences that have no place in the courtroom, its principles and practices cannot be simplified by the extraction of the science that would make them reliable (Larkin, 2015). One-week courses cannot hope to instill the depth of knowledge developed in an academic setting during years of tuition.

Weeklong basic bloodstain pattern classes are dangerous because, even if the instructor is well-qualified, that instructor has no control over the students or their analyses or conclusions after the week ends. Graduates of the course could be 1-week wonders who testify incorrectly on the basis of observing a few isolated stains, or they could realize that 40 h was just the beginning of their training. They could start work as an apprentice with other examiners. They could conduct experiments to verify their findings. It is the job of the attorney to only rely on the analyst who has adequate training and experience, and to refuse to rely on an analyst who has minimum training but has been vetted as an expert witness and is willing to support the attorney’s theory of the case.

Arson analysis in the US parallels this phenomenon. Investigators with little or no scientific background taught other police officers how to determine if a fire was arson or not. They were not scientists and they conducted no experiments; there was no questioning of methods, and there were no reenactments. As addressed in Chapter 3, multiple individuals have been wrongfully convicted of arson because investigators did not do the experiments and did not use scientific methods. Instead, they relied on myths passed from officer to trainee. The problems that developed with arson investigation are mimicked in BPA. What one officer believes and teaches becomes folklore for an entire community of officers.

Is Bloodstain Pattern Analysis Simple?

In her comprehensive 513-page thesis entitled “Bloodstain pattern analysis: scratching the surface,” British doctoral candidate Bethany Larkin examined the nature of bloodstain pattern analysis (BPA) (Larkin, 2015). In the abstract, Larkin opined:

The nature of BPA has given the illusion that its evidentiary significance is less than that of fingerprints or DNA, relying solely on the interpretation of the analyst and focusing very little on any scientific evaluation. Recent preliminary literature studies have involved a more quantitative approach, developing directly crime scene applicable equations and methodology, which have established new ways of predicting the angle of impact, impact velocity, point of origin of blood and blood pattern type

Larkin (2015)

Two points can be made. First, the title of the thesis is telling: BPA is complex, and as reflected in its title, Larkins’ well-researched and drafted thesis, although over 500 pages of informative, dense text, merely scratches the surface. Secondly, it is clear that contemporary jurisprudence has no place for the type of interpretation that relies solely on the analyst’s intuition, and BPA today and in the future must depend on a quantitative approach. In this way, BPA will be better validated as a respected scientific field (Larkin, 2015).

Sample Selection and Documentation

In arson cases, it is common for the arsonist to accelerate the fire by pouring ignitable liquids throughout the structure. Typically, the liquids are poured on the floor, so flooring, if it survives, is what fire investigators usually sample. Selecting a sample that is likely to test positive for ILR (assuming there is any present) requires care, practice, and luck.

Where ignitable liquid has been used, it is often present in overabundance and it may be easily detectable by odor, once the floor has been cleared of fallen debris. It is also possible to see where the ignitable liquid was poured by observing the damage patterns on the floor.

On carpeted floors, there is often a distinct line between burned and unburned areas, although such lines are common in cases where no ignitable liquid was present. Further, because of the way air is entrained into the fire plume of a piece of burning carpet, there tends to be a ‘doughnut’ pattern produced. This results in carpet at the center of the area saturated with ignitable liquid being less damaged than carpet at the edge of the area. Figure 1 shows a typical doughnut pattern. Obviously, the ‘doughnut hole’ presents the best sample. When no ‘doughnut hole’ exists, the sample should include both burned and unburned carpet from the edge of the pattern to its middle.

On hardwood floors, ignitable liquids tend to run in the cracks, as shown in Figure 2. Vinyl floors also may exhibit extra burning where the ignitable liquid has penetrated into seams or lower parts of a textured floor, as shown in Figure 3.

Sample size is usually dictated by the size of the available sample containers. A sample container of 1–5 l will usually be adequate. It should be noted that because the laboratory analysis will usually involve sampling the headspace in a container, filling the container completely is not advisable. If the container is filled completely, it will be necessary for the laboratory to repackage the debris into a larger container for analysis.

When collecting samples, it is imperative that the investigator takes steps to avoid cross contamination or even the appearance of cross contamination. If the tools used for sampling are the same tools used for debris removal, those tools should be decontaminated prior to sampling using a detergent solution. Tools should be cleaned off in between samples to avoid carrying liquid residue from one place to another. If the investigator has any sense of where in the scene there is a higher concentration of ILR, that area should be sampled after the less concentrated areas are sampled.

If arson is suspected, gasoline-powered tools should not be brought into the fire scene. If power is required, a generator should be used for electric tools and the generator should be kept outside. Fire extinguishment crews should be asked whether gasoline-powered fans were used on the fire, and whether it was necessary to refuel the fan at any time. Such data should be documented.

The most important attribute of any fire debris sample is its location. When the investigator makes the decision to sample a particular area, that area should be thoroughly photographed, and the location of each sample should be documented on the investigator's fire scene sketch. Once the sample has been placed in the container, another photograph should be taken showing both the area from which the sample was removed and the sample inside the container.

Disposable latex or nitrile gloves should be used to collect the samples and a new pair of gloves should be used for each sample. The use of gloves should be documented, preferably with a photograph of the discarded gloves at each sample location. Gloves should not be placed in the sample container.

Random sampling is not advisable. There should be a logical reason for the collection of samples. At times, this may mean nothing more than finding the location of doorways and hallways in a structure that has burned to completion.

Plastics and synthetic fibers, because of the way they respond to heat, tend to trap ILR in the melted polymer matrix. Wood flooring also tends to hold onto ILR by adsorbing the residues on the charcoal that is produced as wood burns.

Soils can retain some ILRs, particularly heavy petroleum distillates, almost indefinitely, but some residues in soils are subject to microbial degradation. Soil samples should be refrigerated if there is any significant delay (more than a few days) between collection and submission to the laboratory, or between submission and analysis. Concrete has been known to retain detectable quantities of ILR, but the overlying floor covering (if any) is more easily sampled.

In addition to his or her own olfactory senses, the investigator may employ a hydrocarbon sniffer, a mechanical device that senses hydrocarbons in the air. These devices are not very selective, however, and should not be used in place of laboratory analysis. False positives are common.

An ‘accelerant-detecting canine’ is probably the most effective aid to collecting samples that have a higher probability of testing positive in a laboratory. As with any tool, canines are subject to limitations. The canine responds to scents that it has previously been rewarded for alerting to. If, on a particular scene, a canine responds to pyrolysis products, rather than foreign ignitable liquids, it is likely to respond inappropriately for the rest of the day because it has been rewarded for doing so.

Canines are incapable of identifying different ILRs. This can only be determined by laboratory analysis. There are some investigators who insist that because their canine has demonstrated extreme sensitivity, a negative laboratory test of the sample selected by the canine can be ignored. This is not true. It is the considered opinion of the scientific community (including responsible canine handlers) that canine alerts unconfirmed by laboratory analysis do not constitute valid evidence of the presence of an ILR. Some canines have confirmation rates over 90%, but others fall below 50% on a regular basis. The canine is only a tool.

One useful attribute of this tool is that the animal is willing to spend all day sniffing out a large area, something that most fire investigators are unwilling to attempt. If the scene has been properly cleared prior to the canine's arrival and there is any ILR to be found, the canine will likely find it.

Pyromania

Pyromania involves deliberate fire setting that is preceded by feelings of tension and followed by a sense of pleasure or gratification (American Psychiatric Association, 2013). Individuals with Pyromania are typically fascinated with fire. Fire setting in Pyromania is not done for secondary gains (e.g., criminal or monetary interests), but rather with the goal of enjoying the fire’s esthetic qualities. Theorists have long argued there to be a link between sexual arousal and fire among individuals with Pyromania. Perhaps unsurprisingly, the condition often leads to property damage and legal consequences, and in extreme cases, persons with Pyromania have caused harm to others. Unfortunately, very little is known about the condition, and our clinical understandings of Pyromania are very poorly developed (Geller et al., 1997).

In the United States, Pyromania is estimated to occur in 1% of adults (Vaughn et al., 2010) and between 2.4% and 3.5% of adolescents (Jacobson, 1985; Kolko and Kazdin, 1989; Kosky and Silburn, 1984). Among both adults and adolescents, fire setting is slightly more prevalent in males (Soltys, 1992; Vaughn et al., 2010). Rates of Pyromania among arsonists vary considerably, with estimates between 3.3% and 23% (Lindberg et al., 2005; Repo et al., 1997). Additionally, one study suggested that those with Pyromania tend to be Caucasian, highly educated, employed, and experience high rates of childhood physical and sexual abuse (Grant and Won, 2007).

Research on comorbidity patterns in Pyromania is scarce. Some studies suggested links between fire setting and aggression (Jessor et al., 1977), antisocial behavior (Stickle and Blechman, 2002), and conduct disorder (Geller, 1987); whereas others have shown a relationship between young arsonists and shyness and peer rejection (Chen et al., 2003). Another study found that over half (61.9%) of persons with Pyromania met criteria for a current Axis I mood disorder, and nearly half (47.6%) met criteria for another current impulse control disorder (Grant and Won, 2007).

Introduction

Pyromania, also referred to as pathological fire setting, is a disorder currently included in the Diagnostic and Statistical Manual, 4th edition (DSM-IV), as an impulse control disorder not elsewhere specified. Pyromania is defined by the following criteria according to DSM-IV: (1) deliberate and purposeful fire setting that has occurred on more than one occasion; (2) feelings of tension or arousal preceding a fire-setting act; (3) pleasure, gratification, or relief when setting fires or when watching/participating in the aftermath of the fire; (5) the act of fire setting is not done out of vengeance or for monetary gain; and (6) fire-setting cannot be directly attributed to another mental condition such as conduct or bipolar disorder or impairment due to substance use. Psychosocial problems are common among individuals with pyromania and include impaired functioning and thoughts of suicide. Although pyromania has been documented for almost two centuries, it remains a poorly understood disorder with limited data regarding neurobiology or treatment. This article details what is currently known about the clinical characteristics and treatment of pyromania.

Introduction

Cameron Todd Willingham was executed for the arson deaths of his three infant daughters. Many believe his execution should never have taken place, and as fire science advances, it is becoming clearer that Texas executed an innocent man. Willingham’s case is one of the most scrutinized arson investigation cases in the US due to the serious questions raised regarding the validity of the methodology employed in the investigation and the potential that the fire was a tragic accident, and Willingham was executed for a crime that never was (Grann, 2009; Innocence Project, 2006). The fire and arson investigation evidence played a key role in Willingham’s conviction and has subsequently been the subject of independent investigations by journalists (Grann, 2009; Mills and Possley, 2004), the Innocence Project (2006), and the Texas Forensic Science Commission (2011). Conclusions from these parties concurred that the claims made by the Deputy Fire Marshal and Assistant Fire Chief and relied upon by the jury were unsupported by the evidence and that their testimonies overstepped the purview of their expertise. Though Willingham was not officially exonerated by a court of law, in 2012, former Justice Charlie Baird, who led an inquiry into the state’s activity in the case regarding recanted testimony by a jailhouse informant, concluded that Willingham was wrongly executed (McLaughlin, 2012; Baird, unpublished opinion).

Willingham’s case exemplifies the use of outdated methods in arson investigation and how conclusions based on these methods can form the foundation of a wrongful conviction. It highlights the dangers of confirmation bias, the consequences of investigators drawing conclusions that are unsupported by evidence and research, and the lack of general scrutiny paid by defense counsel, the prosecution, judges, and appellate justices. More research is needed to improve the empirical basis of the methodologies used in fire and arson investigation, and greater resources and effort should be afforded educational programs for legal practitioners who encounter this evidence in court.

What is the difference between fire investigation and arson investigation?

What is the importance of investigating the causes of fire?

What are the techniques used as part of an arson investigation?

Who is responsible for conducting the fire cause investigation?