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Chapter 1 - Introduction Basics of Forensic Science.

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1 Chapter 1 - Introduction Basics of Forensic Science

2 Definition and Scope  Forensic science is the application of science to law: Applies the knowledge and technology of science to the definition and enforcement of laws Laws are continually being broadened and revised to address the alarming increase in crime rates

3 The Role of Science  Science cannot offer final and authoritative solutions to all problems  Social and psychological factors are always present  Science plays an important and unique role in the criminal justice system – ability to supply accurate and objective information that reflects events that have occurred at a crime scene

4 Definition of Forensics Science  The application of science to the to the criminal and civil laws that are enforced by police agencies in a criminal justice system.

5 Diversity of Professions Involved  According to the American Academy of Forensic Science: Criminalistics (synonym for forensic science) Engineering Science General Jurisprudence Odontology Pathology/Biology Physical Anthropology Psychiatry/Behavioral Science Questioned Documents Toxicology

6 Additions to the list of 10:  Fingerprint examination  Firearm and tool mark examination  Technology analysis Computers Digital data analysis  Photography

7 History and Development  Individuals who developed the principles and techniques needed to identify or compare physical evidence  Those who recognized the need to merge these principles into a coherent discipline that could be practically applied to a criminal justice system

8 Early Developments  One of the earliest records: 3 rd century China – manuscript Yi Yu Ji Case solved where a woman was suspected of murdering her husband Evidence showed that he was murdered and she admitted her guilt Chinese were also the first to recognize the potential of fingerprints for identification purposes Often the exception rather than the rule for criminal investigations

9 Early Developments (continued…)  Limited knowledge of anatomy and pathology Hampered the development of Forensic Science until late 17 th and early 18 th centuries  First recorded notes about fingerprint characteristics 1686, Marcello Malpighi Did not acknowledge the value of fingerprints as a method of ID

10 Initial Scientific Advances  1798; “A Treatise on Forensic medicine and Public Health” François-Emanuel Fodéré  Breakthroughs in chemistry also helped 1775; Carl Wilhelm Scheele devised first successful test for detecting arsenic in dead bodies

11 Initial Advances (continued…)  1814; Mathieu Orfila Father of forensic toxicology Published the first scientific treatise (study) on the detection of poisons and their effects on animals  Mid-1800s Advance of several scientific disciplines which advanced the field of forensics  1828; William Nichol – polarizing microscope  1839; Henri-Louis Bayard – microscopic detection of sperm  1839; toxicological evidence first used at a trial  1853; microcrystalline test for hemoglobin  1863; first presumptive test for blood  1850s and 1860s; use of photography in forensics

12 Late 19 th -Century Progress  Beginning to apply knowledge from all scientific disciplines to the study of crime  Anthropology/Morphology (structures of living organisms) applied to the first system of personal identification 1879; Alphonse Bertillon Named anthropometry – systematic procedure for using a series of body measurements as a means of distinguishing one person from another (later replaced by fingerprinting) Father of Criminal Investigation

13 More on the 19 th century…  Bertillon’s anthropometry later replaced by fingerprinting Thomas Taylor (American) said that fingerprints could be used for ID Supported by Scottish physician Henry Faulds 1892; Francis Henry Gaulton undertook the first definitive study of fingerprints and developed a method for classifying them

14 Sherlock Holmes  Not a real person  Legendary but fictional detective in stories by Sir Arthur Conan Doyle  Had a considerable influence on popularizing crime-detection methods  Applied newly developing principles of serology (blood/body fluids), fingerprinting, firearms ID and document analysis in his stories  Doyle’s “A Study in Scarlet” is a classic example (see excerpt)

15 20 th Century Breakthroughs  1901; Karl Landsteiner Discovered ABO blood types  1910; Albert S. Osborne Wrote the first significant text on Questioned Documents (document examination)  1915; Dr. Leon Lattes Developed a simple procedure for identifying the blood group from a dried blood stain Immediately applied to criminal investigations Acceptance of documents as scientific evidence by the courts  1923; Calvin Godddard Used comparison microscope to refine techniques of firearms examination

16 Edmond Locard  French  Formal education in both medicine and law  Started the first police lab in 1910  Founder and director of the Institute of the University of Lyons (France)  Leading international center for study and research in forensic science  Strongly believed every criminal can be connected to a crime by dust particles carried from the crime scene  Locard’s successes helped start police labs in Vienna, Berlin, Sweden, Finland and Holland

17 Locard’s Exchange Principle  When two objects (or people) come in contact with each other, a cross-transfer of materials occurs

18 Modern Scientific Advances  Mid-20 th century Revolution in computer technology Dramatically impacted the field of forensics Wide array of sophisticated techniques for analyzing evidence available  Chromatography  Spectrophotometry (measuring the absorption/reflection of light by materials)  Electrophoresis

19 DNA  Most significant modern advance  DNA typing and profiling  1984; Sir Alec Jeffries developed the first DNA profiling test  1986; DNA profiling used to solve the “Pitchfork” murders of two young English girls (Colin Pitchfork)  Precise ID of a suspect can be determined

20 Computer Databases  Fingerprints  Bullets and shell casings  DNA Significantly reduced the time it takes to analyze evidence and increase accuracy of the results

21 Key Points:  Forensic science is the application of science to criminal and civil laws that are enforced by police agencies in a criminal justice system  The first system of criminal ID was called anthropometry. It distinguished one individual from another based on a series of body measurements  Forensic science owes its origins to individuals such as Bertillon, Gaulton, Lattes, Goddard, Osborne and Locard, who developed the techniques needed to identify or compare physical evidence.  Locard’s Exchange Principle states that when two objects come in contact with each other, a cross- transfer of materials occurs that can connect a criminal suspect to his/her victim.

22 Crime Laboratories - History  1923; Los Angeles Police Dept. crime lab is the oldest Established by August Vollmer  1948; School of Criminology formed at UC- Berkley  1932; FBI established under President Herbert Hoover Offered forensic services to all law enforcement agencies in the USA 1981; Forensic Science research and Training Center for research and development of new techniques/tools/methods Train lab personnel in the latest techniques  Most labs are run locally or at the state level

23 Organization of a Crime Lab  Characterized by rapid growth  Lack of national/regional planning/coordination  Levels: federal, state, county, municipal  Size and diversity makes it impossible to adopt a single model of operation  Most function as part of the local police department, prosecutor, district attorney or medical examiner (coroner)

24 Growth  Several reasons explain the rapid growth of crime labs in the past 40 years Supreme Court decisions requiring scientific, objective treatment of evidence Constitutional rights of suspects (Miranda Rights) Changing judicial requirements due to the staggering increase in crime rates in the USA, especially drug-related crime DNA technology/profiling needs more qualified personnel to analyze the evidence Drug cases still outnumber DNA cases

25 Crime Labs in the USA  Desire to retain local control  Produced a variety of independent labs  Government has no single law enforcement agency with unlimited jurisdiction

26 Crime Labs in the USA (continued) 1.FBI (Department of Justice) Maintains the largest crime lab in the world Ultramodern facility located in Quantico, VA 2.DEA (Drug Enforcement Administration - (Department of Justice) Analyzes drugs seized in violation of federal laws regulating production, sale and transport 3.ATF (Alcohol, Tobacco and Firearms) Analyzes alcoholic beverages Examines documents related to alcohol and firearm excise tax law enforcement Examines weapons, explosive devices and related evidence  Gun control Act of 1968  Organized crime Control Act of U.S. Postal Service Criminal investigations related to the postal service

27 Local and International Crime Labs  Most state governments maintain a crime lab some wit regional or satellite offices (larger states) Try to be cost-effective by not duplicating services  Most countries have created and maintain facilities Organization can vary from country to country Often operate on a fee-for-service basis (some can be private companies)

28 Services of the Crime Lab  Wide variation in total services offered There are many reasons for this  Variations in local laws  Different capabilities/functions of the organization to which the lab is attached  Budgetary and staffing limitations (often very limited)  Some labs have strict functions like processing drug specimens only

29 Basic Services  Physical Science Unit Principles of chemistry, physics and geology ID/comparison of crime-scene evidence  Biology Unit Biologists/biochemists DNA profiling, ID/comparison of biological evidence including botanical materials  Firearms Unit Examines firearms, discharged bullets, cartridge cases, shotgun shells, ammunition, residues, tool marks Determine composition, distance, angles  Document Examination Unit Handwriting/typewriting on questioned documents Ascertain authenticity/source  Photography Unit Examines/records photographic evidence Uses highly specialized techniques such as digital imaging, IR, UV, X-ray to make invisible images/information visible

30 Optional Services Provided by a Full- service Crime Lab  Toxicology Unit Examines body fluids/organs to determine the presence/absence of drugs  Latent Fingerprint Unit Processes and examines fingerprint evidence  Polygraph Unit Lie detecting  Voiceprint Analysis Unit Involves cases of telephone threats or recorded messages Trained analysts tie the voice to a suspect Sound spectrograph creates a voiceprint Sound patterns produced in speech are unique

31 Optional Services (continued)  Crime-Scene Investigation Unit Dispatched specially trained personnel to a crime scene to collect/preserve evidence to be analyzed later in the lab  Includes forensic pathology, entomology and anthropology  Forensic Psychiatry Examines the relationship between human behavior and legal proceedings Behavior patterns of criminals/behavior profile  Forensic Odontology ID victims based on dental evidence Bite mark analysis linked to tooth structure on a suspect  Forensic Engineering Failure analysis, accident reconstruction, causes/origins of fires/explosions  Forensic Computer/Digital Analysis Identifying, collecting, preserving and examining information derived from computers/digital devices

32 Key Points:  The development of crime labs in the USA has been characterized by rapid growth accompanied by a lack of national and regional planning and coordination  Four major reasons for the increase in the number of crime labs in the USA since the 1960s are as follows: 1.The fact that the requirement to advise criminal suspects of their constitutional rights, right to immediate access to counsel has all but eliminated confessions as a routine investigative tool; 2.The staggering increase in crime rates in the USA 3.The fact that all illicit drug seizures must be sent to a lab for confirmatory chemical analysis before a case can go to court; 4.The advent of DNA profiling  The technical support provided by crime labs can be assigned to 5 basic services:  Some crime labs offer optional services such as toxicology, fingerprint analysis, polygraph administration, voiceprint analysis, and crime-scene investigation.  Special forensic services available to the law enforcement community include forensic pathology, entomology, psychiatry, odontology, engineering, computer/digital analysis.

33 Functions of the Forensic Scientist  Analyzing Physical Evidence Apply principles of physical/natural sciences in analyzing evidence  Only physical evidence is free of error/bias Must undergo scientific inquiry – the integrity of evidence comes from applying the scientific method  Not tainted by human error/distortion of facts

34 Functions of the Forensic Scientist (continued) Determining the admissibility of evidence  Frye vs. The United States Procedures/techniques/principles are “generally accepted” by the scientific community  Federal Rules of Evidence Governs admissibility of evidence including expert testimony on a scientific/technical matter if: 1.Testimony is based on sufficient facts/data 2.Testimony is the product of reliable principles/methods 3.Witness has applied the principles/methods reliably to the facts of the case (also used in state courts)

35 Functions of the Forensic Scientist (continued)  Judging Scientific Evidence Judge assumes ultimate responsibility for admissibility/reliability of evidence The Court offers some guidelines 1.Whether the scientific technique/theory can be tested 2.Whether the scientific technique/theory has been subject of peer review/publication 3.Technique’s potential rate of error 4.Existence/maintenance of standards controlling the technique’s operation 5.Whether the scientific technique/method has attracted widespread acceptance within the relevant scientific community  Providing Expert Testimony Performing the analysis of evidence May be required to testify in court about their methods, etc. Education/training is very important

36 Key Points:  A forensic scientist must be skilled in applying the principles and techniques of the physical/natural sciences to analyzing evidence that may be recovered during a criminal investigation.  The cases Frye vs. the United States and Daubert vs. Merrell Dow Pharmaceuticals, Inc. set guidelines for determining the admissibility of scientific evidence into the courtroom.  An expert witness evaluates evidence based on specialized training/experience.  Forensic scientists participate in training law enforcement personnel in the proper recognition, collection and preservation of physical evidence.


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