chapter 1 introduction to forensic science and the law “in school, every period ends with a bell....
TRANSCRIPT
Chapter 1
Introduction to Forensic Science and the Law
“In school, every period ends with a bell. Every sentence ends with a period. Every crime ends with a sentence.”
—Stephen Wright, comedian
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What Do You Know???Quickly and Honestly try this quiz.
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Introduction
How a crime lab works The growth and development of
forensic science through history Federal rules of evidence,
including the Frye standard and the Daubert ruling
Basic types of law in the criminal justice system
Students will be able to:Describe how the scientific method
is used to solve forensic problems Describe different jobs done by
forensic scientists and the experts they consult.
Students will learn:
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Forensic ScienceThe study and application of science to matters of law.Includes the business of providing timely, accurate, and thorough
information to all levels of decision makers in our criminal justice system.
The word forensic is derived from the Latin “forensis” meaning forum, a public place where, in Roman times, senators and others debated and held judicial proceedings.
Forensic Science cannot offer final and authoritative solutions, however it does play an important and unique role in the criminal justice system by using the scientist's ability to supply accurate and objective information that reflects the events of a crime
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General Goals of a Forensic Scientist are:
The general goals of a forensic scientist are:Recognition of physical evidence Identification of physical evidence Individualization of physical evidenceEvaluation of physical evidenceReconstruction of the crime
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Criminalistics vs Criminology
Criminalisticsthe scientific
examination of physical evidence for legal purposes.
Criminologyincludes the
psychological angle, studying the crime scene for motive, traits, and behavior that will help to interpret the evidence
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Crime Lab—Basic ServicesPhysical Science Unit
ChemistryPhysicsGeology
Biology UnitFirearms UnitDocument Examination
UnitPhotography Unit
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Crime Lab—Optional Services
Toxicology UnitLatent Fingerprint UnitPolygraph UnitVoiceprint Analysis UnitEvidence Collection Unit
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Some Forensic Science Services• Forensic Medicine• Forensic Pathology• Forensic Anthropology• Forensic Entomology• Forensic Psychiatry• Forensic Odontology• Forensic Engineering• Cybertechnology
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Forensic MedicineThe application of medicine and
medical science to legal problems Practitioners of forensic medicine are
doctors of medicine with special certification in pathology and forensic pathology
Most of them are Medical Examiners They are concerned with determining
cause and circumstances in cases of questioned death
They also can be involved in matters of insurance claims, and sometimes cases of malpractice
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Forensic OdontologyCommonly called Forensic
DentistryThe application of dentistry to
human identification problems Forensic odontologists are
dentists who specialize in the forensic aspect of their field
They are concerned with the identification of persons based upon their dentition, usually in cases of otherwise unrecognizable bodies or in mass disasters
They also analyze and compare bite mark evidence
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Forensic AnthropologyPersonal identification based on bodily
remains (particularly skeletal) Practitioners are anthropologists who are
interested in Forensic Science Other areas of forensic anthropology
include: Maintaining databases on bodily
structures as functions of race, sex, age, stature, and so forth
Facial reconstruction Interpretation of footprint or shoe-
print evidence
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Forensic ToxicologyThe determination of
toxic substances in human tissues and organs
Much of the work concerns the role toxic agents may have played in causing or contributing to the death of a person
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Trace Evidence AnalysisIncludes all areas of trace and
transfer evidence such as: soil and glass hair and fibers blood physiological fluids arson accelerant and explosive
residues drug identification different patterns and imprints
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Questioned Document AnalysisThe comparison and
interpretation of ...handwritingmechanically produced
material (typing, printing)photocopied material
The analysis of paper, inks, and other materials used to produce documents
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Firearm IdentificationFirearm identification Comparison of markings on
bullets, cartridge cases, and shell cases
Determining if a bullet has been fired from a particular weapon
Toolmark examinations are concerned with the association of a particular impression with a particular tool
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Fingerprint AnalysisClassification of
fingerprints Maintaining fingerprint
databases Development and lifting
of latent prints Comparisons of known
and unknown fingerprints to determine a match
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Major Crime Laboratories
FBIDEAATFU.S. Postal ServiceU.S. Fish and Wildlife Service
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Crime Lab HistoryFirst police crime lab in the world was established in
France in 1910 by Edmond LocardFirst police crime lab in the U.S. opened in 1923 in Los
AngelesThe Scientific Crime Detection Lab was founded in
Evanston, Illinois in 1929The first FBI crime lab opened in 1932
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Major Developments in Forensic Science History
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 brother’s 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 Italy1670—Anton Van Leeuwenhoek constructed the first high-
powered microscope1776—Paul Revere identified the body of General Joseph
Warren based on the false teeth he had made for him1784—John Toms convicted of murder on basis of torn edge of
wad of paper in pistol matching a piece of paper in his pocket
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Major Developments in Forensic Science History
1859—Gustav Kirchhoff and Robert Bunsen developed the science of spectroscopy.
1864—Crime scene photography developed1879—Alphonse Bertillon developed a system to identify people
using particular body measurements1896—Edward Henry developed first classification system for
fingerprint identification1900—Karl Landsteiner identified human blood groups1904—Edmond Locard formulated his famous principle, “Every
contact leaves a trace.”1922—Francis Aston developed the mass spectrometer.1959—James Watson and Francis Crick discover the DNA double
helix1977—AFIS developed by FBI, fully automated in 19961984—Jeffreys developed and used first DNA tests to be applied to
a criminal case
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People of Historical Significance
Edmond Locard (1877-1966)
French professorConsidered the father of
criminalisticsBuilt the world’s first forensic
laboratory in France in 1910Locard Exchange Principle
Whenever two objects come into contact with each other, traces of each are exchanged.
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Crime Scene TeamA group of professional investigators, each trained in a variety of special
disciplines.Team Members
First Police Officer on the sceneMedics (if necessary)Investigator(s)Medical Examiner or Representative (if necessary)Photographer and/or Field Evidence TechnicianLab Experts
pathologist serologistDNA expert toxicologistforensic odontologist forensic anthropologistforensic psychologist forensic entomologistfirearm examiner bomb and arson expertdocument and handwriting experts fingerprint expert
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Scientific Method(as it pertains to criminalistics)
1. Observe a problem or questioned evidence and collect objective data.
2. Consider a hypothesis or possible solution.3. Examine, test, and then analyze the
evidence.4. Determine the significance of the evidence.5. Formulate a theory based on evaluation of
the significance of the evidence
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Complex Reasoning SkillsNecessary to Work Through and Solve Crimes:Deductive and Inductive ReasoningClassifyingComparing and ContrastingProblem SolvingAnalyzing PerspectivesConstructing SupportError Analysis
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Laws that Pertain to the U.S. Criminal Justice System
The U.S. ConstitutionStatutory LawCommon Law or Case LawCivil LawCriminal LawEquity LawAdministrative Law
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Types of Law
Statutory Law - is written or coded law based on the Constitution
Common Law - or case law is made by judges. The US Supreme Court carries the greatest influence. Oncea decision is made in court, it is written down and becomes law.
Civil Law - The law that deals with noncriminal suits broughtto protect or preserve a civil or private right or matter.
Criminal Law - or public law, deals with regulation and enforcement of rights.
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The Bill of RightsGives individuals the right:
To be presumed innocent until proven guilty
Not to be searched unreasonablyNot to be arrested without probable
causeAgainst unreasonable seizure of
personal propertyAgainst self-incriminationTo fair questioning by policeTo protection from physical harm
throughout the justice processTo an attorneyTo trial by juryTo know any charges against oneself
To cross-examine prosecution witnesses
To speak and present witnessesNot to be tried again for the same
crimeAgainst cruel and unusual punishmentTo due processTo a speedy trialAgainst excessive bailAgainst excessive finesTo be treated the same as others,
regardless of race, gender, religious preference, country of origin, and other personal attributes
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Probable Cause
Situation in which a reasonable and prudent person viewing the available information, would conclude that a crime has been committed and that the suspect committed it.
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Miranda v ArizonaIn 1963, Ernesto Miranda, a 23 year old mentally
disturbed man, was accused of kidnapping and raping an 18-year-old woman in Phoenix, Arizona. He was brought in for questioning, and confessed to the crime. He was not told that he did not have to speak or that he could have a lawyer present. At trial, Miranda's lawyer tried to get the confession thrown out, but the motion was denied. The case went to the Supreme Court in 1966. The Court ruled that the statements made to the police could not be used as evidence, since Mr. Miranda had not been advised of his rights.
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Miranda RightsThe following is a minimal Miranda
warning:You have the right to remain silent. Anything
you say can and will be used against you in a court of law. You have the right to speak to an attorney, and to have an attorney present during any questioning. If you cannot afford a lawyer, one will be provided for you at the government’s expense.
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Types of CrimesInfraction - minor
offense or petty crime, no more than 1 year in prison
Misdemeanor a minor crime, less than a felony, usually punished with a fine
Felony - a serious crime, such as murder, punishable by more than one year imprisonments up to execution.
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Steps in Pursuing Justice
Steps in pursuing justice are complex and different depending on jurisdictions .
Crime Scene is investigatedAfter suspect arrested -
BookingInformed of Miranda RightsArraigned before a JudgeBail may be set if deemed appropriateSuspect enters a pleeFuture court dates are set.
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Federal Rules of EvidenceIn order for evidence to
be admissible, it must be:
Probative—actually prove something
Material—address an issue that is relevant to the particular crime
Expert Witness - the person who presents scientific evidence
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Admissibility of Evidence
1923 Frye v. United States
• 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. DowAdmissibility 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 issueThe judge decides if the evidence
can be entered into the trial.
These two rulings have had a great influence on whether scientific evidence can be used in court.
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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 (not necessary to prove in a court of law)
Opportunity—person can be placed at the crime
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“If the Law has made you a witness, remain a man (woman) of science.
You have no victim to avenge, no guilty or innocent person to ruin or save.
You must bear testimony within the limits of science.”
—P.C.H. Brouardel