CH 1d Forensic Scientists n Other Services complete by WhiONJZ

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									NAME: _______________________________________                                            DATE: ___________
FORENSICS CHAPTER 1 NOTES                                                                MR. CARL

FUNCTIONS OF A FORENSIC SCIENTIST
     Applies Science to Law
     Analyzes Physical Evidence
     Gives Expert Testimony
     Trains Law Enforcement
     Available 24-7
ANALYSIS OF EVIDENCE
     They have to…
         o RECOGNIZE
         o IDENTIFY
         o COLLECT
         o PRESERVE
         o EVALUATE
         o INDIVIDUALIZE physical evidence


     DATA is basis of all conclusions
     ACCURATE data is derived from careful collection of evidence
     Poor evidence collection or handling can result in wrong conclusions
         o i.e. – OJ Simpson case
     GI-GO: Garbage in – garbage out
     DOCUMENTATION is essential
     Use of SCIENTIFIC METHODS
     What is evidence vs. coincidence?
     Give WEIGHT (ranking) to results
     Attach a degree of certainty
     Apply results to theories in order to prove or disprove
     Components must add up to THEORY
     It’s ALL about the EVIDENCE!
         o The training & competence of forensic scientists & the sophistication of their equipment have
             little or no value if relevant evidence cannot be recognized, collected, & preserved!


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PHYSICAL EVIDENCE
          The Marsh Test
              o In 1832 police arrested John Bodle for lacing his grandfather's coffee with poison.
              o Chemist James Marsh tested the drink in his laboratory, & confirmed the presence of arsenic by
                  producing a yellow precipitate of arsenic sulfide.
              o But the precipitate was unstable &, by the time of trial, had deteriorated. Without forensic proof,
                  Bodle was acquitted.
          Forensic Scientists must be aware of the demands & constraints imposed by the judicial system.
          Evidence must satisfy the criteria of admissibility that have been established by the courts.
          New scientific techniques to analyze evidence are constantly developed & challenged by the courts until
           proven ‘acceptable’ by the scientific community.
Frye Standard (Frye v. U.S. 1923) - for the results of a scientific technique to be admissible, the technique
must be established & acceptance within the scientific community.
Federal Rules of Evidence (FRE) - any evidence is admissible so long as it assists the jury & is deemed
relevant by the judge.
Coppolino Standard (Coppolino v. State 1968) - the court allows new, sometimes controversial scientific tests
or techniques as evidence IF an adequate foundation can be laid even if the profession as a whole isn't familiar
with it.
Daubert Standard (Daubert v. Merrell Dow Pharmaceuticals 1993). This requires special pre-trial hearings
for scientific evidence. This is very strict & requires knowledge of a test’s error rates, as well as validity &
reliability data. (no junk science!)
Carmichael v. Kumho Tire Co.
          The Carmichaels had a fatal accident when their minivan’s rear tire blew out. One of the passengers died
           & others were severely injured.
          They sued the tire manufacturer, claiming the tire was defective & it caused the accident. Their case
           relied largely on testimony from a tire expert.
          The judge referred to the Daubert standard & found the tire expert's methods not to be ‘scientifically’
           valid, and hence excluded his testimony.
          They lost but appealed & eventually won!




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EXPERT TESTIMONY
      Forensic Scientists are often called upon to act as Expert Witnesses.
      Expert Witness – someone that possesses a particular skill or knowledge on a topic that will aid the
       court in determining the truth.
      The credentials that make someone an ‘expert’ is often ambiguous & highly subjective.
      Expert witnesses must be:
          o Advocates of Truth
          o Objective (no personal opinions)
          o Experienced (# of years in their field)
          o Trained (special courses)
          o Educated (degrees in their field)
      An expert witness is allowed to be challenged by the opposing attorney.
      They cross-examine the expert to find any weaknesses in background & knowledge.
      Even if someone is considered an ‘expert’, a judge or jury might not consider their testimony that
       important anyway.
OTHER FORENSIC SCIENCE SERVICES
Forensic Pathology
      Investigation of sudden, unnatural, unexplained or violent deaths
      Autopsy medical dissection to establish the cause of death (usually performed by ME or coroner)
      Death can be classified as:
          o natural, homicide, suicide, accident or undetermined
      Time of death determined by
          o rigor mortis
                     Muscles relax then shorten & become stiff
                     1st 24 – 36 hours after death
          o livor mortis
                     Heart stops pumping & blood settles in areas of the body closest to the ground.
                     Skin appears dark blue or purple
                     Up to 12 hrs after death
          o algor mortis
                     Body loses heat until it reaches room temperature
                     Influenced by location, victim’ size, clothing, & weather
                     General Rule: 1 hr after death, heat is lost at 1-1.5 degrees per hour

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Forensic Medicine
      Investigation of illnesses that cannot be determined.
      Takes patients symptoms & uses facts to analyze & interpret.
      Usually a last result. Doctors cannot find cause of ailment, so this is employed.
          o HOUSE, M.D.
Forensic Anthropology
      Examine & Identify Skeletal remains
      Bones can reveal
          o species, sex, approximate age, race, skeletal injury
          o Facial reconstruction can help identify “John or Jane Doe”
Forensic Entomology
      Study of insects to estimate the time of death
      Insects lay eggs that hatch into larvae
      Stages of development tell how long ago the eggs were laid
      Temperature & other weather conditions affect the development
Forensic Psychiatry
      Study of human behavior
      Determine if persons are competent to stand trial
      Develop a suspect’s behavioral profile based on previous patterns of other criminals
Forensic Odontology
      Study of teeth characteristics, alignment and the overall structure of the mouth to identify a person
      Bite mark analysis compares marks on a victim to the teeth of the suspect
Forensic Engineering
      Investigation of…
          o structural failures,
          o accident reconstruction
          o causes of fires
          o Attempts to determine if human intervention caused the structural failure
          o Utilizes computer models & architectural models to help courts visualize crime scenes




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