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Dive into the fascinating world of forensic science, from its history to modern techniques and the impact of the "CSI Effect." Discover the diverse professions within this field and the crucial role of science in law enforcement.
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Forensic Science An Introduction
“I want to be a CSI.” • It’s cool, glamorous and fun. You can drive humvees, carry a gun, wear expensive clothes and earn lots of money!
The CSI EffectReference to the phenomenon which raises real world expectations of forensic science and crime scene investigation by general public, victims of crime, jury members and even criminals. 'CSI effect' has juries wanting more evidence By Richard Willing, USA TODAY
Understanding the CSI Effect • Glamorizing the field of forensic science. • Overstating the accuracy of forensic techniques. • Exaggerating the abilities of forensic science. • Inaccurate time frame on when cases get solved. • Many prosecutors, judges and journalists have claimed that watching television programs such as CSI: has caused jurors to wrongfully acquit guilty defendants when the prosecution presents no scientific evidence in support of the case
ForensicScience “The application of science to the criminal and civic laws that are enforced by police agencies in a criminal justice system.” An umbrella term encompassing a myriad of professions that use their skills to help law enforcement officials conduct their investigations.
How and Why is Science Important to Law? As our society has grown more complex, it has become more dependent on rules of law to regulate the activities of its members Science has become a potent tool in the enforcement of civil and criminal law. • Food & Drugs • Automobile Emissions • Purity of water • Levels of toxins
ForensicScience The diversity of professions practicing forensic science is illustrated by the eleven sections of The American Academy of Forensic Science. • Criminalistics • Digital & Multimedia Sciences • Engineering Sciences • General • Jurisprudence • Odontology • Pathology/Biology • Physical Anthropology • Psychiatry/Behavioral Sciences • Questioned Documents • Toxicology
History of Forensic Science Sir Arthur Conan Doyle’s legendary detective Sherlock Holmes applied many of the principles of modern forensic science long before they were adopted widely by police.
History of Forensic Science Mathieu Orfila (1787 – 1853): Toxicology Alphonse Bertillon (1853 – 1914): Anthropometry
History of Forensic Science • Francis Galton (1822 – 1911): Fingerprints • Hans Gross (1847 – 1915): Criminal Investigation • Leone Lattes (1887 – 1954): Bloodtypes • Calvin Goddard (1891 – 1955): Comparison Microscope • Albert S. Osborn (1858 – 1946): Document Examination • Walter C. McCrone (1916 – 2002): Microscopy • Edmond Locard (1877 – 1966): Scientific Method (Locards Exchange Principle)
Locard Exchange Principle "Everywhere you go, you take something with you, and you leave something behind."
Locard Exchange Principle Anytime there is contact between two surfaces, there will be a mutual exchange of matter across the contact boundary
Locard Exchange Principle 'Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value. ‘ -Professor Edmond Locard
1932 The Federal Bureau of Investigation (FBI) crime laboratory is created.
The Growth of Crime Laboratories At present, nearly 400 public crime laboratories operate at various levels of government (federal, state, county and municipal) – more than three times the number of crime laboratories operating in 1966. • Supreme court decisions in the 1960’s were responsible for greater police emphasis on securing scientifically evaluated evidence. • Increase in crime rates in the last 40 years. • All illicit-drug seizures must be sent to a forensic laboratory for confirmatory chemical analysis before the case can be adjudicated. • The advent of DNA profiling
Services of the Crime Laboratory Five Basic Units • Physical Science Unit • Biology Unit • Firearms Unit • Document Examination Unit • Photography Unit Optional Services • Toxicology Unit • Latent Fingerprint Unit • Polygraph Unit • Voiceprint Analysis Unit • Crime Scene Investigation Unit
Physical Science Unit Applies principles and techniques of chemistry, physics, and geology to the identification and comparison of crime-scene evidence. • Uses chemical tests and analytical instrumentation to examine items such as: • Drugs • Glass • Paint • Explosives • Soil
Biology Unit Identification and DNA profiling of: • dried bloodstains • other bodily fluids • hairs • fibers • botanical materials
Firearms Unit Examines: • firearms • discharged bullets • cartridge cases • shotgun shells • ammunition of all types • residue on clothing and other objects
Documentation Examination Unit • Studies handwriting and typewriting on questioned documents to determine authenticity and source. • Analyze paper and ink • Indented writings • Erasures • Obliterations • Burned or charred documents
Photography Unit • Examines and records physical evidence • The following may be required to make invisible information visible: • Digital imaging • Infrared • Ultraviolet light • X-ray photography • Also aids in the preparation of photographic exhibits for courtroom presentation.
Toxicology Unit Examine body fluids and organs to determine presence or absence of drugs or poisons
Latent Fingerprint Unit • Processes and examines evidence for latent (not visible to the naked eye) fingerprints – dactyloscopy
Polygraph Unit • Tool for criminal investigator, not forensic scientist • Handled by people trained in techniques of criminal investigation and interrogation
Voiceprint Analysis Unit • Used in cases involving telephone threats or tape-recorded messages • Use a sound spectrograph (an instrument that transforms speech into a visual graphic display called a voiceprint)
Specially trained personnel dispatched to crime scene (civilian or police) to collect and preserve physical evidence that will later be processed at the crime laboratory. Crime-Scene Investigation Unit
Other Forensic Services • Forensic Psychiatry • Forensic Odontology • Forensic Engineering • Forensic Computer and Digital Analysis
Forensic Psychiatry Examines the relationship between human behavior and legal proceedings
Forensic Odontology • The study of teeth as it relates to the law. • Provides information for identification of victim • Characteristics of Teeth • overall mouth structure • alignment of teeth • bite mark analysis
Forensic Engineering Engineers are concerned with failure analysis, accident reconstruction, causes and origins of fires and explosions
Forensic Computer and Digital Analysis • New and fast- growing field • Identification, collection, preservation, and examination of information derived from computers and other digital devices
Functions of Forensic Scientist 1) Proper Recognition, Collection, and Preservation of Physical Evidence 2) Analysis of Physical Evidence 3) Expert Testimony