Lecture Chapter 8 The Crime Lab PDF

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CHAPTER

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THE CRIME LABORATORY Objectives 1) Define and distinguish forensic science and criminalistics. 2) Understand the importance of an investigator's understanding of crime laboratory capabilities. 3) Describe the three measures of effectiveness of crime laboratories. 4) Distinguish the Frye test from the Daubert test regarding the admissibility of scientific evidence. 5) Explain the role and importance of DNA analysis in criminal investigation and identify the latest technologies in DNA evidence investigation and data banking. 6) Highlight the process of fingerprint identification and comparison. 7) Describe AFIS, IAFIS, and NIBIN. 8) Discuss some of the problems currently associated with police crime laboratories. Overview A crime laboratory is a scientific organization with a closely dedicated mission of aiding the process of criminal justice. It provides this aid by answering, or helping to answer, the vital question of whether a crime has been committed, how and when it was committed, who committed it, and who could not have committed the crime. The criminal laboratory seeks answers such as these through scientific analysis of physical material collected primarily from the scene of crimes or from suspects. While there are more than 350 federal, state and local crime laboratories across the country, the range of services and personnel expertise within the laboratories varies among the organizations. To understand the role of crime laboratories, one must understand their relationship to the scientific community and to the functions of the criminal justice system. There are two distinct activities involved in laboratory work. One is the gathering of evidence at the scene of the crime by evidence technicians or investigators. The second function is the scientific analysis of evidence which occurs in the laboratory. The effectiveness of the latter activity often depends on the efficiency with which the first operation is performed. An important issue addressed in this chapter concerning the function and responsibilities of a crime laboratory is an investigator's expectations. While the laboratory is one of the most valuable tools for a criminal investigator, he/she must be cognizant of its capabilities and limitations. It is not uncommon, for example, for an investigator to send evidence to a laboratory and stall the investigation until the laboratory results are received. Crime laboratories are not intended to replace field investigations. In addition, investigators are often not familiar with the types of evidence that is subject to laboratory analysis. Even the most minute and seemingly insignificant pieces of evidence may be subject to laboratory examination. If investigators are not aware of a laboratory's capabilities, critical pieces of evidence go uncollected, unprocessed, and unused in substantiating guilt or innocence. Because the analysis of evidence is no better than the samples submitted, investigators themselves play an important role in the success of scientific analysis.

Lecture Notes I.

CRIME LABORATORIES A. There are more than 350 federal, state, and local crime laboratories in this country. B. The morgue. One type of crime lab often forgotten is the morgue. A morgue is not just a place that houses the bodies of deceased persons, but it is critical as the place where cause of death is determined. C. Expectations. It is not unusual to find situations in which investigators not acquainted with the services of the crime laboratory expect too much from scientific analysis. 1. The analysis of evidence can be no better than the samples submitted. 2. The investigator therefore has a vital role to play in the success of laboratory examinations.

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MEASURES OF CRIME LABORATORY EFFECTIVENESS The effectiveness of crime laboratory services can be measured in terms of three criteria: quality, proximity, and timeliness. A. Quality is judged largely on the technical capabilities of the laboratory and the abilities of the personnel who staff the laboratory. B. Proximity. It is understood, if not accepted, that most law enforcement agencies cannot afford to staff and maintain a crime laboratory. Studies have shown that evidence submission decreased sharply as the distance from the crime scene to the laboratory increased. C. Timeliness. Timeliness, also extremely important to the investigator, is the third measure of effectiveness of a crime laboratory. D. Admissibility of Examination Results. In 1923, a federal court rendered a decision in the case of Frye v. United States established a standard which provided that, for the results of a scientific technique to be admissible, the technique must be sufficiently established to have gained general acceptance in its particular field. In 1993, the U.S. Supreme Court in Daubert v Merrell Dow Pharmaceuticals, Inc. held that the Frye test was no longer valid in federal courts. Rather, a trial court must determine whether the testimony of an export is based on a scientifically valid methodology and can be properly applied to the facts of the case. 1. Although Daubert only applies to cases in federal courts, a number of states have adopted the Daubert standard. 2. Consequently, the application of Daubert and its aftermath has presented a challenge to crime laboratories to ensure that the standards imposed by the Court are followed in forensic examination so that expert testimony and the results of examinations by crime laboratory personnel will be admissible in both state and federal courts.

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TECHNOLOGIES The speed at which technological advances with forensic applications are developing, expanding, and evolving results in obsolescence.

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Because of the critical role that investigative and forensic sciences play in our nation’s system of justice coupled with the Attorney General’s interest in the rightful conviction of criminals as well as the exoneration of innocent persons, prompted a significant investment in improving efforts in these areas. 1. NIJ has demonstrated the use of teleforensic technology as a means for communicating knowledge from forensic scientists in a crime laboratory to investigators at a crime scene. 2. The NIJ is engaged in many projects to establish standards and protocols for DNA analysis, the development of newer, faster, and more accurate DNA testing methods. DNA Analysis Advances in technology have helped DNA testing to become an established part of criminal justice procedure. Questions about the validity and reliability of forensic DNA test methods have been addressed; and, for the most part, validity and reliability are established. As a result of DNA testing, traditional blood testing and saliva testing have been rendered obsolete because DNA is found in these substances and, if fact, is found in all body tissues and fluids. Identifying and Collecting DNA at a Crime Scene DNA evidence may be found and collected from virtually everywhere at a crime scene. Successes Over the past five years, the number of cases submitted to DNA crime laboratories has escalated. In 2000, DNA crime laboratories received about 31,000 subject cases, an increase from almost 21,000 cases in 1999. Cases with identified suspects accounted for almost three-quarters of the total. DNA Technologies In 1985, Alec Jeffreys and colleagues in England first used DNA in a criminal case. Shortly thereafter, DNA evidence began making appearances in trials in the United States. Contamination Just as contamination is an issue in the collection and packaging of evidence containing DNA, so contamination is a very big issue in the handling of DNA during extraction and examination. Population-Genetics Statistics Just as a fingerprint examiner expert must testify in court that no two people have identical fingerprints, the effectiveness of DNA evidence in court depends on the ability of a witness to explain the probability that no other person, except an identical twin, would have the same DNA sequences. Data Banking and CODIS Today, all U.S. jurisdictions have legislation requiring the data banking of DNA evidence of convicted offenders. 1. In addition to individual-jurisdiction data banking, there is a national investigation support database, developed by the FBI, called CODIS (COMBINED DNA Index System) 2. CODIS is used in national, state, and local index-system networks to link typing results from unsolved crimes with cases in multiple

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jurisdictions or persons convicted of offenses specified in the databanking laws passed by the jurisdictions. Standards, Testing, Research, and Development Laboratory accreditation by the American Society of Crime Lab DirectorsLaboratory Accreditation Board (ASCLD-LAB) in all areas of forensic science required that quality assurance measures be in place at the laboratory. 1. Quality assurance standards have been developed for DNA analysis by the FBI’s DNA Advisory Board. 2. The National Institute of Standards and Technology has tested these performance standards. Human Genome Project The Human Genome Project is a $20 billion international effort to map the 50,000 to 100,000 genes found in the human body. 1. In the long run, this mapping should lead to many medical and forensic breakthroughs. 2. It is anticipated that within a decade, genetics laboratories will be able to determine an individual’s personalized DNA sequence from a blood sample. Post Conviction DNA Testing The contemporary issue in the DNA field is in post conviction cases. Automated Fingerprint Identification System (AFIS) 1. In the early 1970s, the FBI and the National Bureau of Standards conducted feasibility research for establishing an automated fingerprint identification process. 2. AFIS allows law enforcement agencies to conduct comparisons of applicant and suspect fingerprints with literally thousands or millions of file prints in a matter of minutes. 3. AFIS has two major duties: a. First, performing the functions of classifying searching and matching prints. b. Second, is the storage and retrieval of fingerprints data. 4. In July 1999, law enforcement agencies began to have access to the FBI’s Integrated Automated Fingerprint Identification System (IAFIS), a national on-line fingerprint and criminal history database with identification and response capabilities. National Integrated Ballistic Information Network Program (NIBIN). A joint program of the Bureau of Alcohol Tobacco and Firearms (ATF) of the Treasury Department and the FBI in the Department of Justice, the National Integrated Ballistic Information Network integrates all the elements of Ceasefire and Brasscatcher, both former ATF programs, and Drugfire, an FBI program. 1. As each fingerprint is different, a firearm leaves unique identifiable characteristics on expended ammunition. 2. NIBIN compares images of ballistic evidence, both projectiles and casings, obtained from crime scenes and recovered firearms.

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HANDLING EVIDENCE IN THE LABORATORY A. Human Factors In handling evidentiary materials, laboratory personnel—scientists and technicians alike—have always been cautious not to disturb or ruin the viability of the materials for any possible examination that would later prove to be useful. B. Instrumental Analysis The kinds of evidence subject to laboratory examinations are many and varied. 1. Emission Spectrograph. Each element, such as tin, iron, and copper, when properly burned, will give off light that is characteristic of itself and different from the light produced. 2. Mass spectrometer. This instrument is used in analyzing a wide range of forensic specimens, including drugs, poisons, accelerants, explosive residues, and biological samples, by breaking the samples down into chemical “building blocks” and creating profiles of the molecules. 3. Visible Spectrophotometer. This instrument is used for studying color and coloring agents such as dyes and pigments. 4. Infrared Spectrophotometer. This instrument passes a narrow beam of infrared energy through a thin film of the substance being studied. 5. Gas Chromatography. Essentially used as an analytical method for separation and identification of gases or liquids from complex mixtures or solutions, the gas chromatography can analyze organic material such as narcotics, explosives, paints, plastics, inks, and petroleum products. 6. X-Ray Diffraction Spectrophotometer. This instrument is used to identify and compare unknown crystalline substances.

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ATF FORENSIC SCIENCE LABORATORIES A. These laboratories, in addition to analyzing alcohol and tobacco samples, conduct forensic examination in support of the bureau’s explosives, bombing and arson, and illegal-firearm-trafficking investigations, along with major case investigations of state and local authorities. B. Evidence collected at crime scenes of suspected arsons is examined to identify accelerants, incendiaries, and incendiary-device components. C. The bureau has four National Response Teams that respond to major bombings and arson disasters, nationally and internationally.

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THE FBI CRIME LABORATORY The FBI Crime Laboratory is one of the largest and most comprehensive forensic laboratories in the world. A. Reference Files To aid examiners in their work, the FBI laboratory in 1932 established one of the largest reference collections for helping solve cases. 1. These files are of two types: a. standard reference files and collections, which contain known samples of items, generally are from manufactured products. b. reference files of questioned materials, which are composed of items actually arising from cases worked and which may form the

basis for subsequent identification of individuals or their method of operation (MO). 2. Many of these collections and reference files have been computerized to provide better and faster analyses and comparisons. VII.

PROBLEMS IN CRIME LABORATORIES A. Lack of Training B. Lack of Accreditation C. DNA Contamination D. Sentencing Mistakes and Poor Training E. Backlog of Cases F. Scandals and Mistakes Within the FBI Crime Lab: The Madrid Bombing Case G. Code of Ethics...