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Ch. 1- Overview of Forensics
Ms. Figueroa, Fall 2016
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Introduction Forensic science= application of science to the law
First recorded case using forensics dates back to the 13th century (in China) Over the past 150 years, extraordinary advancements were made in technology that have greatly contributed to forensics science.
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Historical Development
Mathieu Orfila ( )- referred to as the Father of Toxicology Alphonse Bertillon ( )- developed the first method of criminal identification called anthropometry (uses body measurements to identify criminals) Sir Edward Richard Henry ( )- developed a fingerprint identification system that categorized fingerprints by specific patterns
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Karl Landsteiner (1868-1943)- discovered blood groups which eventually led to blood typing
Edmund Locard ( )- founder of the Institute of Criminalistics, first university of forensic science; known for his Locard’s exchange principle Albert Osborn ( )- expert in document forgery; wrote a book called Questioned Documents, which is still used today as a reference guide for CSI Calvin Goddard ( )- had an interest in firearms; he invented the comparison microscope which is essential for firearm examination
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Rosalind Franklin ( ), James Watson (1928- ), and Francis Crick ( )- Franklin studied DNA and her diffraction photo of DNA provided significant clues about its structure. Watson and Crick “stole” her photograph and created a structural model of DNA. Today, DNA is used to identify individuals. Alec Jeffreys (1950- )- invented DNA fingerprinting which allows investigators to match DNA to blood and other biological evidence left behind at a crime scene.
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Mathieu Orfila Alphonse Bertillon
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Sir Edward Richard Henry
Karl Landsteiner Sir Edward Richard Henry
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Calvin Goddard and his comparison microscope
Current example of a comparison microscope
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Rosalind Franklin and her DNA photograph (1952)
Watson and Crick and their DNA model (1953)
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A Multidisciplinary Approach
Forensic science incorporates various subject areas like history, math, technology, and natural sciences (biology, chemistry, and physics).
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Scientific Method A logical thought process used to solve problems.
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The CSI Team and Crime Labs
CSI= crime scene investigation CSI Team= made up of legal and scientific experts who work together to process a crime scene and evaluate evidence In bigger cities the team is divided into a field investigation unit and the crime lab scientists
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Processing a Crime Scene
Investigators choose the search method based on the size and location of the crime scene. Zone: building or other structure—homicide, home invasion, robbery, sexual assault, etc. Spiral: large area, no barriers—open field—kidnapping, homicide Line search: large area looking for a large object in a single direction—site of a plane crash Grid: large area looking for a large object in two directions— arson investigation
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Spiral can be outward or inward depending on the case
Spiral can be outward or inward depending on the case. Commonly used for areas with NO boundaries. Line (Parallel) is best for large outdoor scenes. Grid is time consuming but effective. Zone is most effective in houses and buildings. Teams are assigned small zones for searching.
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Evidence Testimonial evidence- the witness testimony used to build a timeline of events Physical evidence- any material collected or observed at a crime scene that could link potential suspects to a crime
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Types of Physical Evidence
Trace Evidence- very small amounts of evidence found at the crime scene Reference Samples- samples from a known source that are used as a basis for comparison Class Characteristics- used to reduce the number of suspects Individual Characteristics- used to match the crime to a single individual
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Chain of Custody Provides documentation of every person who has come into contact with the evidence Creates a paper trail Demonstrates to the courts that the evidence that is being presented at trial is free of contamination, alteration, or substitution
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Landmark Cases Frye v. United States (1923)
These cases changed the way scientific evidence could be presented at trial. Frye v. United States (1923) The Frye Standard — evidence, procedures, and equipment presented at trial must be generally accepted by the scientific community.
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Daubert v. Merrell Dow Pharmaceuticals (1993)
U.S. Supreme Court ruled that the trial judge had ultimate decision-making power regarding expert testimony at trial. The Judge considers the following: 1. Has it been tested? 2. Has it been peer reviewed? 3. What is the rate of error? 4. Is it generally accepted?
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Dr. Carl Coppolino (1963) The court ruled the following:
The fact that a technique, test, or procedure is new does not necessarily mean its findings are inadmissible in court. The expert witness is responsible for providing scientifically valid testimony to support the findings.
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The Judicial Process US Constitution was signed in 1787.
In 1789, 10 amendments were added to the US Constitution. These amendments are called the Bill of Rights. (See Figure on page 17) Sixth Amendment- a person will be tried by an impartial jury of their peers, have the right to counsel, and the right to confront witnesses.
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Arrest In order for law enforcement to arrest or search a suspect, they must show probable cause. There are 4 broad categories of evidence gathering that show probable cause: Observation- may provide a direct link to a crime or detect a familiar pattern. Expertise- law enforcement can have specialized skills and training that they will use to gather evidence.
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Information- from witnesses, informants, or victims
Circumstantial Evidence- evidence that implies, but does not prove, a crime has been committed or that the suspect was involved.
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Before the Trial After the arraignment, pretrial conferences take place between the defendant and the prosecution (called discovery stage). Plea agreements are made (Suspect agrees to plea guilty to a lesser charge for a lighter sentence). At the pretrial, the judge listens to both sides and determines whether there is sufficient evidence to take the case to trial. In some states, a grand jury is convened (more serious charges).
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At the Trial Both sides present their cases to the judge and jury. Prosecution always goes first. Witnesses are called to give testimony, which is cross- examined. In criminal cases, the verdict MUST be unanimous. Appeals- not allowed to present new information. The argument must focus on legal and procedural errors made in the original court.
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