ORGANIZATION of a CRIME LABORATORY

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ORGANIZATION of aCRIME LABORATORY
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Rapid Increase in Crime Labs

• Attributed to an increase in crime rates,
  primarily drug related crimes.
• Drug seizures must be sent to a lab for
  confirmation by chemical analysis before a judge
  can rule on a case.
• Currently over 300 public crime labs operating
  under federal, state, county and municipal
  governments.

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4 major FEDERAL crime labs

• FBI - Federal Bureau of Investigation
• Largest crime lab in the world
• Capable of investigating a broad range of crimes
• DEA - Drug Enforcement Administration
• Primary focus analysis, production, sale,
  transportation of illegal drugs
• ATF - Alcohol, Tobacco, Firearms Explosives
• Primary focus analysis of alcoholic beverages,
  tax law documents, weapons, explosive devices
• Gun Control Act of 1968
• Organized Crime Control Act of 1970
• USPS - U.S. Postal Service

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SERVICES OF A CRIME LAB

• Crime labs vary in the services they provide due
  to
• Differences in local laws
• The labs capabilities
• Budget limitations
• Many crime labs were simply created for
  processing drugs.
• Only a few labs offer a multitude of services.

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Full Service Crime Labs Labs that have the
following units.

• Physical Science Drugs, glass, paint,
  explosives, soil, trace physical evidence.
• Biology DNA, bloodstains, semen, saliva, hair
  fiber comparisons, botanical materials
  (wood/plants).
• Firearms Examines of firearms, discharged
  bullets, cartridge cases, shotgun shells,
  ammunition of all types, clothing (for gun
  residue), tool-mark comparisons.
• Document Examination examines handwritten
  typed/printed documents for authenticity
  (forgery), ink paper analysis.
• Photography Uses digital imaging, infrared,
  ultraviolet, x-ray photography AND courtroom
  photos.

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Other Optional Services

• Toxicology Body fluids organs tested for
  drugs/poisons.
• Intoxilyzer an instrument that detects the
  level of alcohol consumed by someone.
• Latent Fingerprint Unit
• Polygraph lie detection
• Voiceprint Analysis telephone threats recorded
  messages
• sound spectrograph an instrument that
  transforms speech into a visual graphic display
  called a voiceprint.
• Evidence-Collection Unit they only collect they
  do NOT analyze.

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Functions of a Forensic Scientist
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Functions of a Forensic Scientist

• Applies Science to Law
• Analyzes Physical Evidence
• Gives Expert Testimony
• Trains Law Enforcement
• Available 24-7

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Analysis of Evidence

• They have to
• RECOGNIZE
• IDENTIFY
• COLLECT
• PRESERVE
• EVALUATE
• INDIVIDUALIZE physical evidence

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Analysis of 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 (i.e. OJ Simpson case)
• GI-GO Garbage in garbage out
• DOCUMENTATION is ESSENTIAL

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Analysis of Evidence

• 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

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Analysis of Evidence

• Its ALL about the EVIDENCE!
• 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
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Common Examples of Physical Evidence

• Blood, Semen, Saliva
• Hair
• Samples from body organs
• Fingerprints
• Documents
• Serial numbers
• Impressions
• glass

• Soil minerals
• Fibers
• Petroleum residues
• Paint, plastic rubber
• Powder residue
• Firearms explosives
• Wood vegetative fragments

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The Marsh Test

• In 1832 police arrested John Bodle for lacing his
  grandfather's coffee with poison.
• Chemist James Marsh tested the drink in his
  laboratory, confirmed the presence of arsenic
  by producing a yellow precipitate of arsenic
  sulfide.
• But the precipitate was unstable , by the time
  of trial, had deteriorated. Without forensic
  proof, Bodle was acquitted.

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Physical Evidence

• 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.

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Physical Evidence

• 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 tests
  error rates, as well as validity reliability
  data. (no junk science!)

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POLICE LINE DO NOT CROSS
POLICE LINE DO NOT CROSS
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Carmichael v. Kumho Tire Co.

• The Carmichaels had a fatal accident when their
  minivans 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
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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.

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Expert Testimony

• The credentials that makes someone an expert is
  often ambiguous highly subjective.
• Expert witnesses must be
• Advocates of Truth
• Objective (no personal opinions)
• Experienced ( of years in their field)
• Trained (special courses)
• Educated (degrees in their field)

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Expert Testimony

• 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.

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Other Forensic Science Services
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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
• natural,
• homicide,
• suicide,
• accident
• or undetermined

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Time Since Death (TSD) determined by

• rigor mortis
• Muscles relax then shorten become stiff
• 1st 24 36 hours after death
• 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
• 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.
• HOUSE, M.D.

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Forensic Anthropology

• Examine Identify Skeletal remains
• Bones can reveal
• species,
• sex,
• approximate age,
• race
• skeletal injury
• Facial reconstruction can help identify John or
  Jane Doe

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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

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Forensic Psychiatry

• Study of human behavior
• Determine if persons are competent to stand trial
• Develop a suspects behavioral profile based on
  previous patterns of other criminals

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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

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Forensic Engineering

• Investigation of
• structural failures,
• accident reconstruction
• causes of fires
• Attempts to determine if human intervention
  caused the structural failure
• Utilizes computer models architectural models
  to help courts visualize crime scenes

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