Scene examination

Apart from the safety issues normally associated with any chemistry laboratory, there are a number of specific issues associated with explosives and bomb scene examination. An obvious point is the hazards associated with handling and storage of explosives most countries have strict regulations covering this area, and compliance is mandatory. This is not a trivial matter as it is common to receive unknown and unidentified materials, or items that have been subject to physical abuse. 

Additionally, the laboratory may be required to maintain a capability of providing crime scene examinations. The forensic scientist must also be prepared to present expert witness testimony in court, and indeed a sizeable portion of time may be taken... 

The course on crime scene investigation will be offered by the College of Criminal Justice and will emphasize the importance of scene examination and evidence sampling. An improper sampling method can invalidate the results of the forensic laboratory. 

To summarize, the main differences between firearms examination in a terrorist situation and a non-terrorist situation are that in a terrorist situation more cases tend to be of a serious nature, casework involves a wider variety of firearms and related items, more and larger link reports are required, there are different conditions and more difficulties with scene examination, and there is an intelligence gathering aspect to the work. 

During this time he experienced many complex and controversial cases, the vast majority of which were terrorist-related incidents. His main interests include the chemical examinations relating to firearms casework, research and development work arising from same, crime scene examination, health and safety issues, quality assurance, suspect handling and processing, and contamination avoidance procedures both inside and outside the laboratory. 

Scene examination. If there is no standard procedure for the examination of a scene, it is possible that not enough of the space is examined or that essential pieces of evidence may go undetected due to the inadequate search of the area. It is also possible that a scene could be contaminated if it is not regulated to ensure that staff wear appropriate clothing and personal protective equipment and that access to the scene is restricted to certain individuals whose arrival and departure are logged. This can be avoided if general procedures are in place to ensure that these as well as other processes are controlled. 

Donnell RChristian, B.S., spent 15 years with the Arizona Department of Public Safety Crime Laboratoiy, specializing in forensic chemistiy and trace analysis, with emphasis on the clandestine manufacture of controlled substances (i.e., dmgs and explosives). He has responded to hundreds of clandestine lab scenes, examined thousands of exhibits, and provided untold hours of testimony. 

The police will send a scene examiner to each of the receiving hospitals which become in effect crime scenes for forensic purposes. 

The scene examiner will brief all staff about evidence recovery. 

Scene examiners will be appointed solely to deal with each mortuary in order to avoid cross-contamination. 

A scene examiner will attend each post-mortem examination. 

Trace Evidence. Trace evidence (23) refers to minute, sometimes microscopic material found during the examination of a crime scene or a victim s or suspect s clothing (see Trace AND residue analysis). Trace evidence often helps poHce investigators (24) develop connections between suspect and victim and the crime scene. The theory behind trace evidence was first articulated by a French forensic scientist the Locard Exchange Principle notes that it is not possible to enter a location, such as a room, without changing the environment. An individual brings trace materials into the area and takes trace materials away. The challenge to the forensic scientist is to locate, collect, preserve, and characterize the trace evidence. 

Perhaps the simplest examination done is the physical match. A small fragment of wood, plastic, or other material is recovered and fitted into a large piece found on the suspect or at the scene of the crime (39). Other examinations result ordy in demonstrating class characteristics (40). Such information may be used in a prosecution as circumstantial evidence in a trial. However, it is important that the forensic scientist neither inflate nor minimize (41,42) its importance. 

The EPIDOS Register available direcdy on the EPIDOS computer is unique in providing behind-the-scenes information, such as the expected date of grant for a pending patent apphcation, and a record of correspondence between examiner and apphcant. This file is somewhat user-unfriendly, and as a result probably has limited use however, modifications that could increase its use are likely. 

As a prelude to the discussion it is necessary to consider the definition of orientation in terms of the Euler angles, and the definition ofan orientation distribution function in terms ofan expansion ofLegendre functions. These definitions set the scene for examining the information which can be obtained from different spectroscopic techniques. In this review, infra-red and Raman spectroscopy and nuclear magnetic resonance, will be considered. 

A typical court-room scene. Nathan Elias of New York City, the Prosecution s expert witness on chemical production, is testifying. Heinrich Buete-fisch, world s greatest synthetic fuel scientist, is cross examining Elias. On the walls are maps showing I. G. Farben s plants within Germany. 

The newer applications involve the field of biotechnology. Proteins produced by genetically altered organisms such as bacteria must be examined to verify that they are identical to the same proteins produced by humans. Also, analysis of DNA from crime scenes is relatively recent. Indeed, DNA analysis and fingerprinting are powerful tools in modern forensics. 

This is a key issue in every aspect of the forensic examination of explosion scenes, and in subsequent analysis of evidential samples. Unless the results can withstand the meticulous scrutiny properly given to them in a court, they are useless. The requirements include ... 

One can view samples from an explosion scene as belonging to one of two work streams (i) clean and (ii) dirty. Separation between these work streams needs to be established at the earliest possible moment in the process with appropriate laboratory facilities to handle each. The clean work stream contains items which are to be examined for invisible chemical traces of explosives. Such items need protection from any external contamination to a degree commensurate with the sensitivity of the chemical analysis techniques to be employed. The dirty work stream contains items that do not require trace analysis precautions, e.g., scene debris for physical searching. Nonetheless, such items still need to be handled in a way which protects their evidential integrity. Some items can start in the clean stream and then be transferred to the dirty stream, e.g., damaged motor vehicles may first be examined for explosive traces, and then transferred out of the trace examination area to be searched for physical evidence. 

In this kind of question, the examiners provide you with a set of directions for completing a firehouse assignment or operating at a fire scene. The directions might, for instance, provide step-by-step instructions for loading hoses on the apparatus or specify the uses and location of tools. 

We have seen that physical measurements are indispensable in examining zinc and cadmium coordination and this is no less true in the study of sulfur coordination. Whereas IR, NMR and X-ray investigations dominate this scene other, less direct, techniques have been used. 

Trace Evidence. Trace evidence refers to minute, sometimes microscopic material found during the examination of a crime scene or a victim s or suspect s clothing. Trace evidence often helps police investigators develop connections between suspect and victim and the crime scene. The challenge to the forensic scientist is to locate, collect, preserve, and characterize the (race evidence. 

Webb cited data from the CARfile study of the U.S. Department of Transportation in 1985, which reported 1.4% of total accidents and 1.75% of fatal accidents were directly related to sleepiness (7). Lavie and Pollack studied 13,152 reports by the Israeli Police Department of hourly distribution of sleep-related motor vehicle accidents for 8 years, and found 390 injuries directly attributable to sleepiness (8). A special examiner at the scene assigned the reason for the accident. Lavie reported a highest yearly estimate of 1.0% motor vehicle accidents attributable to sleepiness (personal communication to Webb). 

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