Introduction to Forensic Introduction to Forensic Science and the LawScience and the Law

Chapter 1Chapter 1

What Do You Think of What Do You Think of When You Think of When You Think of Forensic Science?Forensic Science?

Forensics Forensics – derived from Latin word – derived from Latin word forensisforensis, meaning forum, meaning forum

Forensic Science or Forensic Science or CriminalisticsCriminalistics – the study and – the study and application of science to lawapplication of science to law

EvidenceEvidence – establishes or disproves – establishes or disproves a facta fact

Crime Lab DepartmentsCrime Lab Departments

Physical sciencePhysical science BiologyBiology BallisticsBallistics Document examinationDocument examination PhotographyPhotography ToxicologyToxicology Fingerprints Fingerprints

SpecialistsSpecialists

AnthropologyAnthropology OdontologyOdontology PsychiatryPsychiatry EngineeringEngineering PolygraphyPolygraphy Entomology Entomology

Crime LabsCrime Labs

Can be at federal, state, or local levelCan be at federal, state, or local level Department of Justice is the largest Department of Justice is the largest

and is run by the FBIand is run by the FBI DEA also operates a lab for the DEA also operates a lab for the

Department of Justice (drug crimes)Department of Justice (drug crimes) ATF operates a lab for Department of ATF operates a lab for Department of

TreasuryTreasury U.S. Postal ServiceU.S. Postal Service U.S. Fish and WildlifeU.S. Fish and Wildlife

Locard Exchange PrincipleLocard Exchange Principle

Whenever two objects come into Whenever two objects come into contact, there is a transfer of contact, there is a transfer of material. Detection methods may material. Detection methods may not find it or it may decay quickly.not find it or it may decay quickly.

Forensics and The Scientific Forensics and The Scientific MethodMethod

ObservationsObservations Inductive Reasoning (experience, Inductive Reasoning (experience,

imagination)imagination) HypothesisHypothesis Deductive Reasoning Deductive Reasoning

(experimentation)(experimentation) Evaluation of Evidence (errors, validity)Evaluation of Evidence (errors, validity) Theory Theory

Types of LawTypes of Law

U.S. Constitution U.S. Constitution Statutory Law – (written, codified law) law Statutory Law – (written, codified law) law

on the books, based on Constitution, on the books, based on Constitution, CongressCongress

Common or Case Law – set by judges, Common or Case Law – set by judges, stare decisisstare decisis recognizes former recognizes former precedentsprecedents

Civil or Private Law – relationships, Civil or Private Law – relationships, punishable by fines or transfer of propertypunishable by fines or transfer of property

Criminal or Public Law – regulation Criminal or Public Law – regulation and enforcement of rights, fines, and enforcement of rights, fines, probation, jail, deathprobation, jail, death MisdemeanorMisdemeanor FelonyFelony

Equity Law – preventive (restraining Equity Law – preventive (restraining order)order)

Administrative Law – IRS, Social Administrative Law – IRS, Social Security Admin. or military Security Admin. or military

Bill of RightsBill of Rights

The right to be presumed innocent The right to be presumed innocent until proven guilty.until proven guilty.

The right to not be searched The right to not be searched unreasonably, either on one’s person unreasonably, either on one’s person or in home.or in home.

The right not to be arrested without The right not to be arrested without probable cause.probable cause.

The right against unreasonable seizure The right against unreasonable seizure of personal property.of personal property.

The right against self-incrimination.The right against self-incrimination.

Steps in Pursuing JusticeSteps in Pursuing Justice CrimeCrime DiscoveryDiscovery InvestigationInvestigation Arrest Warrant (What must we have?)Arrest Warrant (What must we have?) Booking, Fingerprinting, Photograph, Booking, Fingerprinting, Photograph,

Miranda RightsMiranda Rights Arraignment within 72 hoursArraignment within 72 hours Grand Jury or Preliminary or Evidentiary Grand Jury or Preliminary or Evidentiary

HearingHearing IndictmentIndictment Formal trial with juryFormal trial with jury

Different Types of PleasDifferent Types of Pleas

Guilty Guilty Not GuiltyNot Guilty Not Guilty by Reason of InsanityNot Guilty by Reason of Insanity NoloNolo ContendereContendere Double JeopardyDouble Jeopardy

Comprehensive Crime Control Act Comprehensive Crime Control Act (1984)(1984)

A person must be very clear and A person must be very clear and convincing of the fact that he or she convincing of the fact that he or she did not know right from wrong at the did not know right from wrong at the time of the crime.time of the crime.

StatisticsStatistics

50% of people are actually convicted 50% of people are actually convicted of crimesof crimes

25% serve 1+ year in prison25% serve 1+ year in prison 90% plea bargained90% plea bargained

Types of CrimesTypes of Crimes

Infraction – jaywalking, littering, Infraction – jaywalking, littering, traffic violationstraffic violations

Misdemeanors – less than 1 year, or Misdemeanors – less than 1 year, or less than $250-$2500, community less than $250-$2500, community serviceservice

Felonies – 5 years to life, up to Felonies – 5 years to life, up to $100,000, death$100,000, death

Federal Rules of EvidenceFederal Rules of Evidence

Must be probativeMust be probative Must be materialMust be material Must be reliableMust be reliable Expert witness must have credentialsExpert witness must have credentials Hearsay is inadmissible in criminal Hearsay is inadmissible in criminal

cases but is admissible in civil suits.cases but is admissible in civil suits.

Rules for Expert WitnessesRules for Expert Witnesses

The Frye Standard (Frye vs. 1923)The Frye Standard (Frye vs. 1923) The Daubert Ruling (Daubert v. The Daubert Ruling (Daubert v.

Merrell Dow Pharm., Inc., 1993)Merrell Dow Pharm., Inc., 1993)

The Frye StandardThe Frye Standard

Scientific evidence must be given by Scientific evidence must be given by an expert witness and have gained an expert witness and have gained “general acceptance” in the field of “general acceptance” in the field of study.study.

NO PSEUDOSCIENCENO PSEUDOSCIENCE

The Daubert RulingThe Daubert Ruling

Since society had become more complex, Since society had become more complex, e.g. technology, e.g. technology,

Used only in federal courts, but states use Used only in federal courts, but states use it as a guideline.it as a guideline.

Guidelines:Guidelines: Theory or technique must be testableTheory or technique must be testable Must be subject to peer reviewMust be subject to peer review Rate of error must be givenRate of error must be given Technique must follow standardsTechnique must follow standards Must have attracted widespread acceptance Must have attracted widespread acceptance

w/in scientific communityw/in scientific community