INTRODUCTION FORENSIC SCIENCE AND THE LAW CHAPTER 1 OBJECTIVES

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1 INTRODUCTION TO FORENSIC SCIENCE AND THE LAW CHAPTER 1 OBJECTIVES Describe the organization of crime labs in the US and the services they provide Describe the Federal rules of evidence Frye standard and the Daubert ruling Identify the basic types of law in the criminal justice system Describe the different jobs done by forensic scientists and the experts they consult 1

2 In school, every period ends with a bell. Every sentence ends with a period. Every crime ends with a sentence. - Stephen Wright (commedian) What do you think this means? What is Forensic Science? the study and application of science to matters of the law forensic scientists examine the association among people, places, things and events involved in crimes Note: forensic science and criminalistics are interchangeable (synnonemous) 2

3 criminalistics the scientific examination of physical evidence for legal purposes criminology includes the psychological angle: studying the crime scene for motive, traits, and behavior that will help to interpret the evidence evidence: anything that tends to establish or disprove a fact (testimony, documents, objects, matter) A forensic scientist studies the different types of evidence found at a crime scene and testifies as an expert witness at a trial or hearing - presents data, weighs evidence, gives an impartial opinion to the court 3

4 Crime Laboratories vast majority are public (funded through taxes at federal, state, local level) provide services for police, prosecutors, and other law enforcement agencies Department of Justice maintains the FBI, DEA and ATF labs FBI largest crime lab in world (Quantico, VA) DEA 7 labs nationally investigate illicit drug activities inside / outside of the US ATF 3 regional labs crimes involving alcohol, weapons, explosives, tobacco and organized crime forensic scientists use crime labs to help them examine evidence Basic Services Provided by the Crime Lab Physical science unit Chemistry Physics Geology (drugs, soil, glass, apint, blood spatter patterns, other trace physical evidence) Biology unit biology biochemistry microbiology (body fluids, DNA, blood factors, hair, fibers and plant life) Firearms and ballistics unit (tool marks, weapons, firearms, and bullets) Document examination unit (handwriting, typing, word processing, computer applications, paper and ink) Photography unit The most common types of evidence examined are drugs, firearms, and fingerprints. 4

5 CRIME SCENE TEAM a group of professional investigators, each trained in a variety of special disciplines Team members: First police officer on the scene Medics (if necessary) Investigators Medical examiner or representative (if necessary) Photographer and/or field evidence technician Lab experts: pathologist serologist DNA expert toxicologist forensic odontologist forensic anthropologist forensic psychologist forensic entomologist firearm examiner forensic palynologist document and handwriting experts bomb and arson experts fingerprint expert palynologist polygraph experts Methodology of Forensics fundamental principle of investigation at every crime scene Locard principle (Edmond Locard forensic investigator early 1900 s) a criminal can be connected to a crime by trace evidence collected at the crime scene whenever two objects come into contact there is always a transfer of matter 5

6 Whenever two objects come into contact, there is always a transfer of material. The methods of detection may not be sensitive enough to demonstrate this, or the decay rate be so rapid that all of transfer has vanished after a given time. Nonetheless, the transfer has taken place ~ Locard forensic scientists must be methodical in their work observe general characteristics of the evidence and then observe specific features that link evidence to a crime and a suspect Scientific Method (as it pertains to criminalists) 1. Observe a problem or questioned evidence and collect objective data. 2. Consider a hypothesis or possible solution involves inductive reasoning, experience and imagination 3. Examine, test, and then analyze the evidence support or refute hypothesis 4. Determine the significance of the evidence. 5. Evaluate and verify all evidence consideration must be given to standardization, reproducibility, validity, reliability and accuracy validity. 6. Formulate a theory based on evaluation of the significance of the evidence must stand up to scientific and legal scrutiny 6

7 Criminal Justice and the Law laws = code of conduct have been in existence since beginning civilizations based on what a society deems important modern laws are a result of a long history of social customs, rules, practices, legal decisions and rulings that are considered acceptable United States Constitution supreme document and final authority on laws pertaining to individual rights, and on the power of the government to create laws and to create limits on punishments federal laws overrule state laws Laws of the criminal justice system statutory law (written or codified law) law on the books legislative acts declaring, commanding or prohibiting something based on the Constitution common law (case law) the body of law made up of judicial opinions and precedents (decisions made in previous cases or superior courts that are used as a basis to justify decisions made in other cases) stare decisis to stand by the decision previous legal decisions are to be followed 7

8 civil law (private law) deals with noncriminal suits brought to protect or preserve a civil or private right or matter more concerned with assessing blame than establishing intent formal means for regulating relationships between individuals, businesses, organizations, agencies of government involving matters as property, contracts, marriage, divorce, negligence, products manufactured with hidden hazards preponderance of evidence is required to convict criminal law (public law) regulation and enforcement of rights, setting the acceptable limits of conduct in society - concerned with offenses against an individual that are deemed offensive to society misdemeanor minor crime, less than a felony, usually punished with a fine or confinement other than a prison - theft, minor assault and battery, possession of small amounts of illegal drugs 8

9 felony major (serious) crime punishable by more than one year of imprisonment up to execution (death penalty) - murder, rape, armed robbery, serious assault, dealing in illegal drugs, fraud, auto theft, forgery - punishable by fines, community service, probation, incarceration or life in prison / capital punishment (extreme cases) - prosecution must prove guilt beyond a reasonable doubt to convict a suspect 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 9

10 Types of Crimes violation: any time a law has been broken (breach of right, duty or law) - can be minor or major crimes classified as infractions, misdemeanors, or felonies infraction: violation of a rule or law that is not punishable by prison - minor offense or petty crime; penalty is usually a fine misdemeanor: minor crime punishable by fine ($250 - $2500) or no more than one year in jail - first offense of DUI, vandalism, shoplifting, simple assault, trespassing, prostitution felony: major crime punishable by fines (up to $ ) and/or more than one year in prison arson, aggravated assault, burglary, robbery, homicide, rape Steps in Pursuing Justice Complex and confusing different jurisdictions (federal, state, local), different state rules and procedures, the type of crime, extenuating circumstances, prior hx crime committed crime must be discovered and a suspect identified investigation of crime info collected (crime scene documented, searched for evidence and analyzed) report of findings given to prosecutor further investigation arrest warrant issued if the elements of a crime are present 10

11 suspect in custody taken to police department for booking and informed of Miranda rights (for questioning) individual is brought before a magistrate, judge or commissioner for arraignment within 72h court may appoints a public defender, inform suspect of charges and rights and set bail (if appropriate) suspect offers a plea guilty, not guilty, not guilty by reason of insanity, double jeopardy (tried for the same crime in the same court) or nolo contendre (no contest) suspect brought before a judge if a felony preliminary hearing prosecution presents case, accused can cross-examine witnesses and produce favorable evidence judge considers the offense and defendant s record decides whether there is enough evidence for trial, or to dismiss or reduce charges for insufficient evidence some states may use a grand jury (jury decides if there is enough evidence to go to trial) instead of a preliminary hearing especially felonies if the jury decides to indict a suspect, trial date is set 11

12 What are the elements of a crime? define elements, booking, Miranda rights (warning), arraignment, bail, nolo contendere, preliminary (evidentiary) hearing, grand jury, indict, plea bargaining *** all information can be found on pgs textbook Federal Rules of Evidence In order for scientific evidence to be admitted in a court of law, it must be: probative: actually proves something material: addresses an issue that is relevant and significant to the particular crime evidence is admissible if it is reliable and if the person who presents it is believable and competent 12

13 hearsay - testimony based on what others have said not what was seen, heard or known - is not admissible in criminal court not reliable and cannot be crossexamined (is admissible in civil suits) expert witness presents scientific evidence must establish credibility through credentials, background and experience two legal decisions had great influence on whether scientific evidence can be used in court - Freye Standard and Daubert Ruling Admissibility of Scientific Evidence The Frye Standard ( general acceptance test ) 1923 case Frye v. United States scientific evidence is admissible at trial only if the methodology or scientific principle (opinion is based) if it is generally accepted by the relevant scientific community only applies to new or novel scientific methodologies 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. 13

14 pseudoscience (junk science) theories based on flawed and/or untested hypotheses not derived from or tested by the scientific method (not reproducible) The Daubert Ruling 1993 case Daubert v. Dow revision of the Frye standard endorses the classical definition of the scientific method The judge decides if the evidence can be entered into the trial. 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 theory or technique follows standards 14

15 Facets of Guilt To prove a case, the MMO must be established; it must be shown that the suspect had: motive - person had a reason to do the crime (not necessary to prove in a court of law) means - person had the ability to do the crime opportunity - person can be placed at the crime scene 15