Forensic crime scene investigation

Lawrence Kobilinsky, Ph.D., is a professor of biology and immunology at the City University of New York John Jay College of Criminal Justice. He currently serves as science advisor to the college s president and is also a member of the doctoral faculties of biochemistry and criminal justice of the CUNY Graduate Center. He is an advisor to forensic laboratories around the world and serves as a consultant to attorneys on major crime issues related to DNA analysis and crime scene investigation. 

Spennemann, D. H. R. and Franke, B. (1995). Archaeological techniques for exhumations A unique data source for crime scene investigations. Forensic Sci. Int. 74, 5-15. 

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. 

DNA, commonly referred to as the blueprint of Ufe, passes along hereditary information to offspring and directs aU life processes. DNA also plays a key role in forensic science, made popular by TV shows such as CSI Crime Scene Investigation. However, DNA fingerprinting isn t just a gimmick used in Hollywood scripts it is a valuable tool in solving real-world crimes. 

Forensic science is the application of scientific principles to the analysis of numerous types of evidence, most commonly evidence collected at a crime scene. Crime scene investigators, usually police officers, collect evidence at the crime scene and submit it to a crime laboratory for analysis by forensic scientists. 

The popular television series CSI Crime Scene Investigations, which features the work of forensic evidence investigators, including pathologists, premiered in 2000 and spawned several spinoffs and imitators. 

P. Moore, The Forensics Handbook The Secrets of Crime Scene Investigation. New York Barnes Noble Books, 2004,... 

Aaron was shot in the ieg, the criminais fied, and Debra caiied 911. Aaron was taken to the hospital and luckily, he survived. The police arrived to investigate the crime and file a report, while a crime scene investigator collected evidence that included several strands of hair. The hair samples were sent to a crime lab, where Ron, a forensic toxicologist, begins the process of analyzing the samples. 

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. 

Searching a crime scene is a complex process (25), involving poHce, crime scene technicians, and forensic scientists. The procedure requires careful documentation, collection, and preservation of the evidence. Trace evidence (26) in criminal investigations typically consists of hairs (27,28) both natural and synthetic fibers (qv) (29,30), fabrics glass (qv) (31,32) plastics (33) sod plant material budding material such as cement (qv), paint (qv), stucco, wood (qv), etc (34), flammable fluid residues (35,36), eg, in arson investigations explosive residues, eg, from bombings (37,38) (see Explosives and propellents), and so on. 

Emergency responses to incidents involving weapons of mass destruction are much different from responses to incidents involving conventional explosives. For example, while the debris from conventional explosives may be extensive and present hazards to the individuals responding, such as fires or structural instability, the materials are not inherently hazardous. In this situation, the site can be secured and forensic investigations can be conducted similarly to investigations at other crime scenes. 

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. 

The major question posed now is how can soils be used to make accurate forensic comparisons when we know that soils are highly complex and that there are thousands of different soil types in existence For example, according to the USDA, which collects soil data at many different scales, there are more than 50,000 different varieties of soil in the United States alone. Parent material, climate, organisms, and the amount of time it takes for these properties to interact will vary worldwide. First of all, soil samples must be carefully collected and handled at the crime scene and then compared by a soil scientist with forensic science experience to ensure that the soil samples can be useful during an investigation. 

Finally, what is a third important ingredient in the forensic science training format I see it as a need to guide the student in understanding the role of science in the total scheme of the administration of justice. For years we have heard many eminent forensic scientists make strong appeals for the scientist to remain aloof from the crime scene, from the investigator, from the legal counsel, from the accused, and from the philosophy of the law itself. The scientist is told that his objective interpretation of the evidence will be a sufficient end in itself. 

Suppose that a suspect in a theft investigation is a researcher in a biology laboratory. The suspect frequently works with formaldehyde, CH20. Police officers find traces of a substance at the crime scene, and send samples to the Centre for Forensic Science. The forensic analysts find that the substance contains a compound that has an empirical formula of CH20. Will this evidence help to convict the suspect Not necessarily. 

The need for the identification of textile fibers in forensic science is a common one. Many types of crimes, when investigated, yield fibers as physical evidence. Crimes in which fibers may be deposited at the scene include robbery, breaking and entering, homicide, rape, assault, and hit-and-run accidents involving a victim. 

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