 |  Criminal Investigation, 8/e Charles R. Swanson,
University of Georgia
Neil C. Chamelin,
Assistant State Attorney, Second Judicial Circuit
Leonard Territo,
University of South Florida- Tampa
The Crime Laboratory
Chapter OutlineI. FORENSIC SCIENCE AND CRIMINALISTICS DEFINED (See Slides 7-2 and 7-3) The terms "forensic science" and "criminalistics" are often
used interchangeably. A. Forensic science is that part of science applied to answering legal questions. B. Criminalistics which is one of the branches of forensic science, deals
with the study of physical evidence related to a crime. II. CRIME LABORATORIES: PROGRAMS AND PERSONNEL DISTRIBUTION (See Slides
7-5, 7-6 and 7-7) 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 is critical
on the forensic scene 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. III. MEASURES OF EFFECTIVENESS OF CRIME LABORATORIES (See Slides 7-5,
7-6, and 7-7) 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 Dawber 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. (See Slide 7-8) 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. IV. TECHNOLOGIES (See Slide 7-9) The speed at which technological advances with forensic applications are developing,
expanding, and evolving makes their description immediately obsolete. A. 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 also heavily into many projects to establish standards and
protocols for DNA analysis, the development of newer, faster, more accurate
DNA testing methods. B. DNA Analysis (See Slides 7-10, 7-11 and 7-12) 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. 1. DNA evidence may be found and collected from virtually everywhere at
a crime scene. 2. Even though DNA may be collected from a crime scene, it may not be submitted
to a laboratory for a variety of reasons. 3. 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. 4. 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. 5. Population Genetics - Statistics. Just 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. 6. Databanking and CODIS. Today, all U.S. jurisdictions have legislation
requiring the data banking of DNA evidence of convicted offenders. (See Slide
7-13) a. In addition to individual-jurisdiction data banking, there is a national
investigation support database, developed by the FBI, called CODIS (COMBINED
DNA Index System) b. CODIS is used in the national, state and local index-system networks
to link typing results from unresolved crimes with cases in multiple jurisdictions
or persons convicted of offenses specified in the data-banking laws passed by
the jurisdictions. 7. Standards, Testing, Research, and Development Laboratory accreditation by the American Society of Crime Lab Directors-Laboratory
Accreditation Board (ASCLD-LAB) in all areas of forensic science required that
quality assurance measures be in place at the laboratory. a. Quality assurance standards have been developed for DNA analysis by the
FBI’s DNA Advisory Board b. The National Institute of Standards and Technology has tested these performance
standards. 8. 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. a. In the long run, this mapping should lead to many medical and forensic
breakthroughs. b. It is anticipated that, within a decade, genetics laboratories will be
able to determine an individual’s personalized DNA sequence from a blood sample. 9. Post Conviction DNA Testing (See Slide 7-14) The contemporary issue in the DNA field is in post conviction cases. C. Automated Fingerprint Identification System (AFIS) (See Slides 7-15 and
7-16) 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 (See Slide 7-17) a. First is 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 (IAFIA), a national on-line
fingerprint and criminal history database with identification and response capabilities.
(See Slide 7-18) D. National Integrated Ballistic Information Network Program (NIBIN). (See
Slide 7-19) 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. V. HANDLING EVIDENCE IN THE LABORATORY A. Human Factors In handling evidentiary materials, laboratory personnel—scientists and technicians
aline—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, or petroleum products. 6. X-Ray Diffraction Spectrophotometer - This instrument is used to identify
and compare unknown crystalline substances. VI. ATF FORENSIC SCIENCE LABORATORIES (See Slide 7-20) 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. VII. THE FBI CRIME LABORATORY (See Slide 7-21) 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 what
is now 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 of 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 (Mos). 2. Many of these collections and reference files have been computerized
to provide better and faster analyses and comparisons. |
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2002 McGraw-Hill Higher Education