Critically Analyzing Fire Investigation Difficulty - Essay Example

? Critically Analyzing Fire Investigation Difficulty Critically Analyzing Fire Investigation Difficulty Thesis: critically examine the statement that fire investigation is one of the most difficult studies undertaken routinely by the forensic scientists (ide,2004;215) Outline Introduction Introduction to key terms Fire Investigation – one of the difficult studies Processes to help towards better fire investigation Examples: Reliability of Fire pattern study proved through Researches Use of latest Technologies Conclusion Work Cited Introduction This paper focuses on the critical examination of the statement: “Fire investigation is one of the most difficult studies undertaken routinely by the forensic scientist.” It starts with the introduction of the terms fire investigation and forensic science and goes on to highlight what steps have been taken by the latest investigators to easy up the work of fire cause and debris Analysis. It highlights the major breakthroughs and discoveries by scientists in this side. P.S. The case study have been carried out in light of ONLY difficulty attached with finding the origin and real cause of fire and how latest technologies and methodologies have eased up the work for Forensic Science. The article agrees to the difficulty of fire investigation, but highlights how many researches have proved the authenticity of latest methodologies used in the fire investigation (making the work easy for the forensic scientists). The article focuses on: 1. Fire pattern Analysis (movement & intensity) 2. V pattern (upward & downward movement) 3. Accelerants 4. Gas Chromatography 5. Researches proving the reliability of above methods. Introduction to Key terms Fire Investigation mainly refers to the origin and cause investigation of fire it is primarily the analysis of fire related incidents. After fire extinguishers or fire fighters extinguish a fire, an investigation is thereby launched to determine the origin along with the cause of the explosion and fire. Investigations in to such incidents demand a systematic approach and knowledge of fundamentals of fire science. Forensic science (is a transformative cycle, Forensic Science Under the Microscope) is an application of a broader spectrum of sciences to answer queries of interest to a legal system. This might be in relation to any criminal or any civil action. The word forensic is a derivation from the Latin adjective forensic, meaning "before or of the forum." In Romans times, a criminal charge would have meant presenting the case before a certain groups of public individuals in the forum. Both the accused and the accuser would give speeches of their sides of the story. The individual one with the best argument and delivery would have won the case. In modern use, the term "forensics" is closely associated with scientific field that is the word "forensics" is used with "forensic science". Fire Investigation one of the difficult studies Fire investigation also referred at times as the origin and cause investigation study is the examination of fire related incidents. It starts up once the fire is extinguished with the objective of piecing everything together to find out the real causes, bits of fire. Fire investigation is considered to be as one of the most difficult areas of the forensic sciences to practice. (Forensic Science information) However unlike most forensic disciplines, even the usual question of whether a crime has occurred is even not normally obvious. Moreover, the entire process of fire investigation needs to be undertaken just to find out if the case involves arson or not. Here the primarily difficulty of determining arson occurrence (or carrying out appropriate fire investigation) arises due to fire destroying most of the key evidences of its origin. Despite this school of thought, today we see the successful fire investigations being carried out. In the modern world today, forensic scientists have learnt to utilize tiny bits of what remains to find out the origin or the real cause of fire. In short it could be said that though, fire investigation is perceived as a difficult area of study many forensic scientist have progressed to make it easier for future genres. Processes to help towards better fire investigation Fire Pattern Analysis Fire pattern analysis can be utilized in fire and the arson investigations and consist of the analytical methodologies that are based on expert interpretation of the discernable patterns occurring after a fire event. (Guide for Fire & Explosion Investigations) Burn Patterns Fire patterns can be defined as the visible or the measurable effects of what remains after a fire. Most patterns are usually seen as recorded on two dimensional surfaces, at the place where such surfaces intersect with the three dimensional fire. Fire patterns are helpful in recording the happenings during such time period of a fire but might not be able to provide information of sequence of pattern development. What the investigators see after the fire is generally the total record of what actually happened. In this case it is not of necessity to see the sequential order of creation of each pattern. The after effects of hot gases, heat smoke and flames on materials are the material forming the fire patterns that could be used to trace the course of the fire, usually by reversing that process, one could establish the actually area of origin of the fire. These effects can generally be categorized as follows: 1. The surface deposits (with no such irreversible effects on any substrate); 2. The surface thermal effects including the scorching or melting, discoloration; 3. The Charring – surface; 4. The Penetration this is the charring below surface; 5. Consumption of charring completely through an actual or material destruction. Use of all of the above fire patterns could help establish various insights into specific details for determining the origins or cause of fire. “V” Patterns V patterns are used in the fire investigation studies. These are the intensity, impingement, and direction of the fire plume’s travel forming lines or areas of demarcation on ceilings, floors walls and other materials. These demarcations can occur in such locations where a combination of heat, smoke, and flames impinge upon several materials, forming intersections of unaffected and affected areas. Common examples would cover smoke layers deposited on walls along with the plume patterns on walls. These demarcations can differ depending on the type of material exposed, rate of heat release, fire temperature and ventilation. Areas of the material loss are supportive in determining demarcations. They might simply deposits on surfaces or with the result of heat transferring causing melting, charring, scorching, or ignition at the affected area. As the smoke and hot gases rises from fire, they would form mixture with the surrounding air, with such mixing zone becoming wider as the hot gases rises above the fuel. Entrainment therefore mixes and spreads in to the rising column so generally forms a “V” shape approximately 30° in width (that could be i.e., half-angle of 15?) . (Fire and Materials) FORENSIC CHEMICAL ANALYSIS Detection of Fire Accelerants from Debris The major role of the forensic scientist in fire investigation focuses on the detection of accelerants these cover mainly gasoline, explosives, or the incendiary devices that might be the cause to start and sustain a suspicious fire. An accelerant is any flammable material that can be used to start the fire. Accelerants can be solids, liquids and even be gases, with gasoline among the most commonly used. Solid accelerants would generally cover paper, highway flares, fireworks and black powder. Butane (the cigarette lighter fuel), natural propane, and other natural gases are examples of the gaseous accelerants, which might not leave any residue at the fire scene. However, the gases must be contained and then transported, as severed gas lines or spent containers might serve as a critical physical evidence in such case. Liquid accelerants might fall into two broad categories: the petroleum distillates, which include gasoline and the other petroleum products; along with the nonpetroleum products such as methanol, turpentine and acetone (used in nail polish remover), Gasoline and kerosene are not just single hydrocarbons but mixtures of various different components with same volatilities. The volatility of accelerant is one important consideration in combustion process, determining just how much residue will be left along with how quickly it will evaporate once the fire is out. Moreover, related to volatility is the flash point, the temperature at which a liquid will ignite if enough vapor to form an ignitable mixture. If we take it for gasoline, the flash point is naturally -50°F (-45.56°C). At a fire scene, the presence of such accelerants can be determined using greater number of procedures including chemical color tests, trained dogs and portable instruments or sensors. Materials such as the wood and carpet generally absorb liquid accelerants, so samples of such materials can harbor as greater valuable evidence. It is vital for the investigator to get control samples since such carpets and synthetic materials can at times interfere with or lead to even false answers during laboratory analysis. Evidence from scene is usually collected in glass jars or tightly sealed metallic paint cans to prevent vapors from escaping. This is important and generally easier process to avoid loss of evidence. The main tool that are used to detect or to identify the liquid accelerants is that the gas chromatography (gc) that is coupled to either a mass spectrometer (ms) or a flame ionization detector (fiD). Analysis with the help of such instruments produces results that are distinctive for common petroleum distillates. Such patterns are then identified with comparison to standards of known composition. These patterns obtained from such evidence can then be influenced by the weathering along with the microbial activity, particularly if the sample is on the soil or the vegetation. Weathering occurs as the lighter (more volatile) elements of this accelerant evaporate. The greater time these samples sit before they are collected, the more severe is the weathering effect. Examples: Reliability of Fire pattern study proved through Researches Burn Patterns Reliability In the one of the testing by Shanley and Kennedy resulted that “patterns which remained on room surfaces and furniture items were the ones useful for determining the actual point of origin of these fires.” (Program For The Study Of Fire Patterns) Kennedy, Hopkins, Hicks, Gorbett, and Abney also have studied pattern formations on standard witness surfaces with consistent fuel packages and established that “though the time to reach every pattern differed, the amount of the mass consumed and the heat produced by the fire and the ignitability of the witness surface plus the heat energy imparted were the decisive factors in re producing a consistent, similar pattern.” (Advanced Fire Pattern Research Project: Single Fuel Package Fire Pattern Study) Additionally, an “a pattern point, or the point of enough heat impartation onto the surface by the flame plume had form visible pattern was even reliably determined.” A study by Kennedy, Hopkins, Hicks, Gorbett, , and Abney studied on “the development of three pattern formations namely: Columnar, Triangular (Inverted cone), and Conical . . . [and established] the evolution of fire pattern phases that any fuel package goes through in times of a fire are valid.”(Advanced Fire Pattern Research Project) V Patterns Reliability Test study by the Factory Mutual Research Corporation (FMRC) suggested greater scientific insights into the formation of V patterns. In FMRC’s a closer examination of the fire plume’s lines of demarcation revealed distinct areas of damage to the wall surfaces, called the fire propagation boundary. This is a visually distinguishable line with the heavy paralysis of the surface ends. Actual fire testing by the study of FMRC documents the close correlation between the fire propagation boundaries and critical heat flux boundary. This is the location of the boundary at which the minimum heat flux is either at or below the point where a flammable vapor air mixture is produced. Analyzing the shape of these fire patterns resulting from plumes can provide valuable insight into fire investigation study. For instance, the greatest ceiling that is damaged is often the one in the plume impingement area which directly above the fuel source, a point from which gas movement vector would points directly back to the fire’s origin. In simple two dimensional views in which the fire plume comes in contact with and damage the wall surfaces, damaged patterns forming lines of demarcation would frequently appear. These lines are referred to as V shaped fire patterns, based on their characteristic which is upward sweeping shape. The references of NFPA 921, Kirk’s Fire Investigation, along with the Forensic Fire Scene Reconstruction have just dispelled past misconceptions with regard to the shape and geometry of V patterns, once they are thought to relate to rapidity of the fire growth. The shape of any V pattern is generally related to the ventilation effects, heat release rate, ignitability, geometry of the fuel, and combustibility of the affected surfaces, and the intersection with horizontal surfaces. The key to understanding these lines and angles that these lines of demarcation make is to allow them to help in documenting the fire plumes. There are several mathematical relationships that exist which can provide an insight into this analysis helping in finding the origin of the fire. Accelerants or Gas Chromatography Reliability The utilization of a Accelerant Detector Canine to search for fire scenes reduces the amount of hours the forensic science or the arson investigators spends on the fire investigation. (That is Accelerant reduces difficult areas of fire investigation making us investigation easier)(Fire and Arson Investigator) The Canine teams with the use of accelerant (used in laboratories) can survey the large areas in almost half the time what it takes any investigator to complete a search of the same area. (Detector Dogs Hot On The Scent) This task is easier and completed due to the mobility and the keen senses that the canines possess. Making use of the canine detectors to search for ignitable liquids would thereby reduce the number of samples that are required by any evidence technician. History of properly trained along with maintained canine teams have proved that positive reactions by such canines yields a higher probability that ignitable liquids are present.( Canine Accelerant Detection Teams: Validation and Certification) This reduces difficulty as Investigators no longer would just have to rely on the "pot shot" samples based on either fire behavior and or burn patterns. Furthermore, canine searches of the fire scenes are also identifying the locations where the perpetrator has poured such ignitable liquids and that have not ignited. Use of latest Technologies Photography Images often constitute to the primary evidence evident from a fire scene. Fire scenes “must be photographed carefully sufficient to record their general patterns, features and their relationships with any other objects nearby. This is of utmost important in finding whether there is evidence of fire spreading from possible ignition sources to various other combustible objects or to the adjacent structures. (Developing and Using Demonstrative Exhibits in Support of the Crime Scene Analysis) A single photograph therefore would not be considered as a sufficient enough to judge the situation of any fire scene. Use of Camera (digital and professional) would help bring more insight information thereby easing the case process. Technology Use of technology plays a vital role in determining the set patterns and their movements. However, emerging 3D technology has not still been employed to acquire and therefore examine fire patterns. In most instances, researchers would utilize thermocouple trees and even heat flux transducers to capture temperature data, measuring resulting patterns by using heat and flame vector analysis and depth of calcinations calculations, and also documenting findings with digital, 35mm still and direct observations, written notes, and video photography, diagrams. Conclusion Forensic Scientists have observed that many people have only limited knowledge of forensic science works and tasks that it performs. (Crime scene to court the essentials of forensic science) It can therefore be concluded that though the fire investigation is perceived by people as one of the difficult area of forensic study but with the use of above methodologies and technologies the investigation becomes easy. As researches have proved the reliability of these methods, they could be used to draw on reliable analysis from any fire debris. This has brought much light in to studies which were often overlooked by Investigators. Identifications of such areas would help more once the arsenal case goes to trial. Once these samples have been gathered from the fire scene, these samples would be rechecked by the canine team before sealing the evidence container, to make sure proper evidence is collected because if only proper evidence is collected then only the result is good. Work Cited 1. Butterworth, James R., ‘Accelerant Detector Canines...Then and Now’ in Fire and Arson Investigator, volume 46, Number 2 2. DeHaan, supra note 45, at 295; see also Iris Dalley, Developing and Using Demonstrative Exhibits in Support of the Crime Scene Analysis in PRACTICAL CRIME SCENE ANALYSIS AND RECONSTRUCTION, 255 (2009) 3. Dehan, John D., "Canine Accelerant Detection Teams: Validation and Certification", p 1?14. 4. ‘Fire investigation in Forensic Science information, in UK .2011 < http://forensicscienceinformation.co.uk/Fire-Investigation.php > 5. H-Z. 1984. An Investigation of Fire Plume Impingement on a Horizontal Ceiling. 1 - Plume region. Fire and Materials. Volume 8, Number 1, pp. 28-39. 6. James H. Shanley Jr., Patrick M. Kennedy, Program For The Study Of Fire Patterns, < http://www.fire.nist.gov/bfrlpubs/fire96/PDF/f96156.pdf > 7. McVicar, M. (2008). "Headspace Analysis Using ATD-GC-MS FIR-09.5". Unpublished Manual, Chemistry Section, Centre of Forensic Sciences and Northern Regional Laboratory, Ontario Canada. 8. Natl. Fire Protection Assoc., NFPA 921 Guide for Fire & Explosion Investigations (2008)(hereinafter NFPA 921) at 3.3.60 9. Paul C. Giannelli, Forensic Science: Under The Microscope, 34 OHIO N.U. L. REV. 315 (2008). 10. Ring, Elizabeth, "Detector Dogs Hot On The Scent", p 20. 11. Stauffer, E., Dolan, J., Newman, R. (2008). "Extraction of Ignitable Liquid Residues from Fire Debris". Fire Debris Analysis. Academic Press. pp. 387–426. 12. W. Hicks, G. Gorbett, P. Kennedy, R. Hopkins, W. Abney, Advanced Fire Pattern Research Project < http://people.eku.edu/gorbettg/index _files/ADVANCEDFIRE PATTERNPMKChanges10-12-06.pdf. > 13. William Hicks, Gregory E. Gorbett, Patrick M. Kennedy, Ronald L. Hopkins, William M. Abney, Advanced Fire Pattern Research Project: Single Fuel Package Fire Pattern Study, 221 14. White,peter (2004) 2nd ed ides chapter crime scene to court the essentials of forensic science Read More