Introduction to Forensic Science

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Introduction to Forensic Science to the Law

• Chapter 1

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Forensic Science

• It is the study and application of science to
  matters of law (criminal and civil)
• Includes the business of providing timely,
  accurate, and thorough information to all levels
  of decision makers in our criminal justice system
• Also called criminalistics

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Criminalists vs Criminologists

• A criminalist examines physical evidence for
  legal purposes
• Criminologists study the crime scene for motive,
  traits, and behavior as to help interpret the
  evidence
• They learn to think like criminals

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Forensic Scientists

• Applies the principles and techniques of the
  physical and natural sciences to the analysis of
  the many types of evidence that may be recovered
  during a criminal investigation
• May also provide expert court testimony
• Known as an expert witness
• Individual whom the court determines possesses
  knowledge relevant to the trial

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The Crime Lab

• Characterized by rapid growth due to
• Supreme Court decisions in the 1960s placing
  greater emphasis on scientifically evaluated
  evidence
• Accelerated drug abuse
• Initiation of DNA profiling
• 350 public crime labs exist at federal, state,
  county, and municipal levels

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Crime Lab Services

• 5 exist
• Physical science
• Chemistry
• Physics
• Geology
• Biology
• Firearms
• Document
• Photographic

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Physical Science Unit

• Incorporates the principles of chemistry,
  physics, and geology to identify and compare
  physical evidence

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Biology Unit

• Applies the knowledge of biological sciences in
  order to investigate blood samples, body fluids,
  hair, and fiber samples

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Firearms Unit

• Investigates discharged bullets, cartridge cases,
  shotgun shells, and ammunition

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Document Unit

• Provides the skills needed for handwriting
  analysis and other questioned document issues

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Photographic Unit

• Applies specialized photographic techniques for
  recording and examining physical evidence

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Other Crime Lab Services

• Toxicology Unit- examines body fluids and organs
  for the presence of drugs and poisons
• Latent Fingerprint Unit- processes and examines
  evidence for latent fingerprints
• Polygraph Unit- conducts polygraph or lie
  detector tests
• Voiceprint Analysis Unit- attempts to tie a
  recorded voice to a particular suspect
• Evidence Collection Unit- dispatches specially
  trained personnel to the crime scene to collect
  and preserve physical evidence

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Other Forensic Science Services

• Forensic Pathology- concentrate closely on the
  understanding of types and causation of injuries
  and causes of sudden and unnatural death
• Deals with the different stages of death
• Rigor mortis- stiffening of the body (occurs
  within first 24 hours)
• Livor mortis- settling of blood closest to the
  ground (occurs up to 12 hours)
• Algor mortis- results in loss of heat

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Other Forensic Science Services

• Forensic Anthropology-concentrates on the
  identification of deceased individuals whose
  remains are decomposed, burned, mutilated or
  otherwise unrecognizable
• Forensic Entomology- is the study of insects and
  their relation to a criminal investigation,
  commonly used to establish the time of death
• Forensic Psychiatry- work with courts in
  evaluating an individual's competency to stand
  trial, defenses based on mental diseases or
  defects (e.g., the "insanity" defense), and
  sentencing recommendations

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Other Forensic Science Services

• Forensic Odontology- evaluates teeth to determine
  the identification of the deceased
• Forensic Engineering- investigation of materials,
  products, structures or components that fail or
  do not operate/function as intended, causing
  personal injury for example
• Cybertechnology- involves the examination of
  digital evidence

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Major Crime Labs

• FBI- Federal Bureau of Investigations
• DEA- Drug Enforcement Agency
• ATF- Bureau of Alcohol, Tobacco, Firearms, and
  Explosives
• US Postal Service
• US Fish and Wildlife Service

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The Crime Lab

• History
• First established in 1910 by Locard
• First police crime lab established in 1923 in Los
  Angeles, CA
• Scientific Crime Detection Lab established in
  1929
• First FBI crime lab opened in 1932

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Developments in Forensic Science

• 700s AD- Chinese used fingerprints to establish
  identity of documents and clay sculptures
• 1000- Roman courts determined that bloody palm
  prints were used to frame a man in his brothers
  murder
• 1149- King Richard of England introduced the idea
  of the coroner to investigate questionable death
• 1200s- A murder in China is solved when flies
  were attracted to invisible blood residue on a
  sword of a man in the community
• 1598- Fidelus was first to practice forensic
  medicine in Italy

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Developments in Forensic Science

• 1670- Anton van Leeuwenhoek constructed the first
  high powered microscope
• 1776- Paul Revere identified the body of General
  Joseph Warren based on the false teeth he had
  made for him
• 1784- John Toms convicted of murder on basis of
  torn edge of wad of paper in pistol matching a
  piece of paper in his pocket
• 1859- Gustav Kirchoff and Robert Bunsen developed
  the science of spectroscopy
• 1864- Crime scene photography developed

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Developments in Forensic Science

• 1879- Alphonse Bertillion developed a system to
  identify people using particular body
  measurements
• 1896- Edward Henry developed the first
  classification system for fingerprint
  identification
• 1900- Karl Landsteiner identified human blood
  groups
• 1904- Edmond Locard formulated his famous
  principle, Every contact leaves a trace
• 1922- Francis Aston developed the mass
  spectrometer

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Developments in Forensic Science

• 1959- James Watson and Francis Crick discover the
  DNA double helix
• 1977- AFIS developed by FBI, fully automated in
  1996
• 1984- Jeffreys developed and used the first DNA
  tests to be applied to a criminal case

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People of Historical Significance

• Albert Osborn- developed the fundamental
  principles of document examination
• Walter McCrone- utilized microscopy to examine
  evidence
• Hans Gross- wrote treatise on criminal
  investigation
• Edmond Locard- considered the father of
  criminalistics responsible for Locards exchange
  principle
• States that when a criminal comes in contact with
  an object or a person, a cross transfer of
  evidence occurs

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People of Historical Significance

• Mathieu Orfila- father of forensic toxicology
• Alphonse Bertillion- devised first scientific
  system of personal identification
• Francis Galton- conducted first definitive study
  of fingerprints and their classification
• Leone Lattes- developed a procedure to determine
  blood type from dried bloodstains
• Calvin Goddard- used a comparison microscope to
  determine if a particular gun fired a bullet

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The Crime Scene Team

• A group of professional investigators, each
  trained in a variety of special disciplines
• Team members include
• First police officer on the scene
• Medics (if necessary)
• Investigator(s)
• Medical examiner
• Photographer and/or Field Evidence Technician
• Lab Experts

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• pathologist serologist
• DNA expert toxicologist
• forensic odontologist forensic anthropologist
• forensic psychologist forensic entomologist
• firearm examiner bomb and arson expert
• document and handwriting experts
• fingerprint expert

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Laws that Pertain to the US Criminal Justice
System

• The US Constitution
• Statutory Law
• Common Law or Case Law
• Civil Law
• Criminal Law
• Equity Law
• Administrative Law

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US Constitution

• Supreme body of laws that governs our country
• Overrules the constitutions of individual states

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Statutory Laws

• Are written laws as enacted by a government body
  such as Congress
• Are based on the Constitution

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Common Law

• Also known as case law
• Are made by judges
• Makes for predictability and consistency in how
  the law is applied

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Civil Law

• Also known as private law
• Deals with relationships between individuals
  involving properties or contracts
• Regulates noncriminal relationships between
  individuals, businesses, agency of government,
  and other organizations
• Includes contracts, marriages, divorces, wills,
  property transfers, negligence, and products
  manufactured with hidden hazards
• More concerned with assigning blame than intent

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Criminal Law

• Also known as public law
• Deals with regulation and enforcement of rights
• Concerned with offenses against an individual
  that are deemed offensive to society
• Cases tried are always the person vs the state
• Those laws that are broken fall into 1 of 2 main
  categories
• Misdemeanor- is a minor crime such as theft,
  minor assault and battery, or possession of small
  amounts of illegal drugs
• Felony- is a major crime such as murder, rape,
  armed robbery, serious assaults, dealing in
  illegal drugs, fraud, auto theft, or forgery

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Equity Law

• Remedial or preventive law
• Are for cases not covered by common law
• Restraining orders
• Injunctions

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Administrative Law

• Laws established by governmental agencies such as
  the IRS, Social Security Administration, or the
  military

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The Bill of Rights

• The right to be presumed innocent until proven
  guilty
• The right not to be searched unreasonably, either
  on ones person or in ones home
• The right not to be arrested without probable
  cause
• The right against unreasonable seizure of
  personal property
• The right against self-incrimination
• The right to fair questioning by police

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The Bill of Rights

• The right to protection from physical harm
  throughout the justice process
• The right to an attorney
• The right to trial by jury
• The right to know any charges against oneself
• The right to cross examine prosecution witnesses
• The right to speak and present witnesses

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The Bill of Rights

• The right not to be tried again for the same
  crime
• The right against cruel and unusual punishment
• The right to due process
• The right to a speedy trial
• The right against excessive bail
• The right against excessive fines
• The right to be treated the same as others,
  regardless of race, gender, religious preference,
  country of origin, and other personal attributes

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Steps in Pursuing Justice

• If a crime is committed these are the steps to
  take while pursuing justice
• Police investigate what happened
• Information is collected
• Crime scene is documented and searched for
  evidence
• All info is assembled into a report and sent to
  DA
• Investigation continues until probable cause is
  established
• An arrest warrant is issued for the suspect
• The suspect is arrested
• Individual is booked, fingerprinted, photographed
  and informed about his/her rights

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The Miranda Rights

• Miranda v. Arizona (1966)
• Before a law enforcement officer may question a
  suspect regarding the possible commission of a
  crime, he or she must inform the detainee about
  his or her Miranda rights, making sure the
  detainee understands them

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The Miranda Rights

• Warning of Rights
• You have the right to remain silent and refuse to
  answer questions
• Anything you do or say may be used against you in
  the court of law
• You have the right to consult an attorney before
  speaking to the police and to have your attorney
  present during questioning now or in the future
• If you cannot afford an attorney, one will be
  appointed for you before any questioning if you
  wish
• If you decide to answer questions now without an
  attorney present, you will still have the right
  to stop answering at any time until you talk to
  an attorney
• Knowing and understanding your rights as I have
  explained them to you, are you willing to answer
  my questions without an attorney present?

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Steps in Pursuing Justice

• Person is brought before a magistrate judge who
  informs the individual of the charges, his/her
  rights, and bail
• The person may also enter a plea of guilty, not
  guilty, not guilty by reason of insanity, double
  jeopardy (been tried for same crime in same
  court), or nolo contendere (no contest)
• If a plea of guilty is entered, the person is
  brought before a preliminary or evidentary
  hearing (no jury present)
• Most states use a grand jury
• Will determine if there is enough evidence to
  bring the accused to a formal trial
• The prosecutor presents evidence and the grand
  jury (16-23 citizens) decide the fate of the
  accused
• If the grand jury decides there is enough
  evidence, a trial date will be set

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Steps in Pursuing Justice

• If a plea of not guilty by reason of insanity is
  entered, the defendant will have to prove, by
  clear and convincing evidence, that at the
  time of the commission of the acts constituting
  the offense, the defendant, as a result of a
  severe mental disease or defect, was unable to
  appreciate the nature and quality or wrongfulness
  of his acts
• Crimes must show intent- the insanity plea
  removes intent

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Steps in Pursuing Justice

• Sometimes, the DA will plea bargain with the
  accused
• The defendant works out a deal with the DA
• May reduce jail time

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Types of Crimes

• All crimes are violations (breach of a right,
  duty, or law)
• 3 types
• Infractions
• Misdemeanors
• Felonies

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Infractions

• Minor offense or petty crime
• Is less serious than a misdemeanor
• Examples include
• Jaywalking
• Traffic violations
• Littering
• Penalty is usually a fine

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Misdemeanors

• Cases are tried in court
• Punishable by no more than 1 year in jail
• Examples include
• A first offense of drunk driving, vandalism,
  shoplifting, simple assaults, trespassing, or
  prostitutions
• Fines range from less than 250 to 2500
• Community service is also part of the sentence
  sometimes

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Felonies

• Cases are tried in court
• Punishable from 5 years to life
• Some states offer death penalty
• Examples include
• Arson, aggravated assault, burglary, robbery,
  homicide, and rape
• Fines may be up to 100,000
• Probation may also be determined

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Federal Rules of Evidence

• Probative
• In evidence law, tending to prove something
• Material
• In evidence law, relevant and significant.
• Hearsay
• Testimony given by a witness who relates not what
  he or she heard, saw, or knew personally, but
  what others have said
• Is not admissable in the court of law

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Admissibility of Evidence

• 1923 Frye v. US
• Scientific evidence is allowed into the courtroom
  if it is generally accepted by the relevant
  scientific community.
• The Frye standard does not offer any guidance on
  reliability.
• The evidence is presented in the trial and the
  jury decides if it can be used.

• 1993 Daubert v. Dow
• Admissibility is determined by
• Whether the theory or technique can be tested
• Whether the science has been offered for peer
  review
• Whether the rate of error is acceptable
• Whether the method at issue enjoys widespread
  acceptance
• Whether the opinion is relevant to the issue
• The judge decides if the evidence can be entered
  into the trial

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Facets of Guilt

• Try to prove
• Means- person had the ability to do the crime
• Motive- person had a reason to do the crime
• Does not have to be proved in a court of law
• Opportunity- person can be placed at the crime