Clothing forensics

The major role of the forensic scientist is to analyze submitted evidence for the purposes of characterization and identification. For example, a blue fiber collected from the scene may be submitted to the trace evidence section, where forensic scientists characterize the fiber (for example, by its dimensions, color, cross-sectional shape) and then identify the type of fiber (for example, nylon, polyester, acrylic). Furthermore, when a known sample is available (such as fibers from the suspect s clothing), forensic scientists compare it with the unknown sample (collected from the crime scene) to determine if the two most likely originated from a common source. This process of characterization, identification, and comparison requires multiple stages of analysis, ranging from visual examination to instrumental analysis. 

Forensic scientists work with physical evidence, ie, "data presented to a court or jury in proof of the facts in issue and which may include the testimony of witnesses, records, documents or objects." Physical evidence is teal or tangible and can HteraHy include almost anything, eg, the transient scent of perfume on the clothing of an assault victim the metaboHte of a dmg detected in the urine of an individual in a driving-under-the-influence-of-dmgs case the scene of an explosion or bullets removed from a murder victim s body. 

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. 

C. sativa is cultivated for several purposes. Actually, the main legal purpose is the production of hemp fibers and pulp. From these materials paper, clothes and ropes are made [12] and several Western coimtries have already legalized the cultivation of C. sativa for these purposes. In research, the drug-type of C. sativa is also cultivated, however, only for the investigation and determination of forensic studies for chemotype separation. The growth for medicinal purposes is hardly performed, hi the Netherlands C. sativa is cultivated for medicinal purposes under strictly controlled regulations by the company Bedrocan. In this chapter we discuss basic aspects of the cultivation of C. sativa and the optimization of THC content in the plant. 

Our personal civilian security is greatly enhanced by many contributions from chemistry and chemical engineering, often through integrated R D efforts with teams of scientists from many disciplines. Law enforcement employs forensic tools that rely heavily on chemical analysis, and emergency response teams use a variety of protective clothing and equipment that rely on modern materials chemistry and engineering. As mentioned above, individual security extends to chemical detection methods in the home. 

Trace analysis of explosives is of major importance in forensic and environmental applications [6]. In forensics, the applications include analysis of postexplosion residues and identification of traces of explosives on suspects hands, clothing and other related items. The results of these analyses are not only necessary for the investigation of a bombing but can also serve as evidence in court. 

The analysis of explosives has rather obvious forensic implications. HPLC applications have been published concerning both the analysis of postblast residues in the attempt to identify the explosive used, and the detection of explosive traces on the hands and clothing of a suspect in order to provide... 

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. 

Janaway, R. C. (2002). Degradation of clothing and other dress materials associated with buried bodies of both archaeological and forensic interest, in Advances in Forensic Taphonomy Method, Theory, and Archaeological Perspectives (W. D. Haglund and M. H. Sorg, Eds.). Boca Raton, FL CRC Press, 279-402. 

Komar, D. and Beattie, O. (1998). Post-mortem insect activity may mimic peri-mor-tem sexual assault clothing patterns. /. Forensic Sci. 43, 792-796. 

Forensic biochemists perform blood typing and enzyme tests on body fluids in cases involving assault, and also in paternity cases. Even tiny samples of blood, saliva, or semen may be separated by electrophoresis and subjected to enzymatic analysis. In the case of rape, traces of semen found on clothing or on the person become important evidence the composition of semen varies from person to person. Some individuals excrete enzymes such as acid phosphatase and other proteins that are seldom found outside seminal fluid, and these chemical substances are characteristic of their semen samples. The presence of semen may be shown by the microscopic analysis for the presence of spermatozoa or by a positive test for prostate specific antigen. 

The Northern Ireland Forensic Science Taboratory (N1FST) was involved in the assessment of such ammunition for the police, and tests were conducted to compare lead levels using Nyclad and conventional ammunition. Unfortunately, the tests results did not survive the terrorist explosion at the laboratory in September 1992, but the overall conclusion was that the claims made relating to the reduction of lead were more than justified. (Other tests involving the examination of the perimeter of bullet holes in cloth that were caused by Nyclad bullets revealed that cobalt was repeatedly and readily detected by FAAS.)... 

The sequence of events associated with FDR examination is usually as follows the initial incident, apprehension of suspects, transporting of suspects to police station, sampling of suspects at police station (swabs of hands, face, head hair, and seizure of clothing), submission of items to the laboratory, sampling of clothing at the laboratory, sample preparation, analysis of samples, interpretation of results, preparation of statement of witness report, and the presentation of forensic evidence in court. 

Although there is extensive literature on the identification and detection of propellants, little work has been devoted to the combined analysis of organic and inorganic FDR recovered from hands and clothing in forensic casework. The analysis of organic FDR has concentrated on the detection of NG and 2,4-DNT by HPLC/PMDE. The HPLC/PMDE system requires a... 

The remainder of the book details chemical aspects of forensic firearms casework with particular emphasis on the detection of gunshot residues (GSR)/firearm discharge residues (FDR)/cartridge discharge residues (CDR) on a suspect s skin and clothing surfaces. The development of an analytical method to routinely examine samples from terrorist suspects for both firearms and explosives residues is described. 

A. Tracqui, P. Kintz, B. Ludes, C. Jamey and P. Mangin. The detection of opiate drugs in non-traditional specimens (clothing). Report of ten cases. /. Forensic Sci. 40, 263-265, 1995. 

Thin-layer chromatography Is commonly employed to determine pigmentation of plants, using extracts of leaves. This method is also used to detect pesticides or insecticides in foods and has been instrumental in analysis of the dye composition of fibres from clothing in forensic investigations. 

A forensic method involves the identification of blood group from a trace of blood on the victim s clothing. 

Figure 6.10. DNA and Forensics. DNA analysis can be used to establish guilt in criminal cases. Here, DNA was isolated from bloodstains on the pants and shirt of a defendant and amplified by PCR. The DNA was then compared to the DNA from the victim as well as the defendant using gel electrophoresis and autoradiography. DNA from the bloodstains on the defendant s clothing matched the pattern of the victim, but not that of the defendant. The frequency of a coincidental match of the DNA pattern on the clothing and the victim is approximately 1 in 33 billion. Lanes X, Ikb, and TS = Control DNA samples lane D = DNA from the defendant jeans = DNA isolated from bloodstains on defendent s pants shirt = DNA isolated from bloodstains of the defendant s shirt (two different amounts analyzed) V = DNA sample from victim s blood. [Courtesy of Cellmark Diagnostics, Germantown MD.]...

If the blood images were made by contact with wounds, it follows that the cloth was used to enfold a body. We have independent evidence that the cloth was used in this way. The mapping function, which maps body-only image density to expected cloth-body distance and the two-dimensional placement of the image on the cloth, offers a consistent argument that the Shroud enfolded a human-body shape. If we couple this argument with the testimony of the forensic pathologists, we can say more not only was it a human form, but further, it was a human body. 

Forensic chemistry is concerned with the application of the principles of chemistry and related sciences to the examination of physical evidence collected at scenes of crimes, e.g. blood stains, paint fragments, bomb residue, clothes, drug samples and hair. The samples could provide conclusive evidence linking a suspect to a crime. Results from chemical analysis are usually conclusive and can be used to support eye witness testimony especially when trials take place many months or even years after the offence. 

Forensic science and its application in criminal investigative technology are used to help clarify criminal cases. Textiles can play an important role here, usually in the form of clothing but also including household and automobile textiles, furnishings and in rare cases also technical textiles, for example strings and ropes used to... 

Figure 5.9 DNA and forensics. DNA isolated from bloodstains on the pants and shirt of a defendant was amplified by PCR, then compared with DNA from the victim as well as the defendant by using gel electrophoresis and autoradiography. DNA from the bloodstains on the defendant s clothing matched the pattern of the victim but not that of the defendant. The frequency of a coincidental match of the DNA pattern on the clothing and the victim is approximately 1 in 33 billion.

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