a Compare and contrast the history of scientific forensic techniques used in collecting and submitting evidence for admissibility in court eg Locards Exchange Principle Frye standard ID: 686773
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Slide1
Forensic Science
SFS1. Students will recognize and classify various types of evidence in relation to the definition and scope of Forensic Science.
a. Compare and contrast the history of scientific forensic techniques used in collecting and submitting evidence for admissibility in court (e.g.
Locard’s
Exchange Principle, Frye standard,
Daubert
ruling).Slide2
ESSENTIAL QUESTIONS
What is forensic science?What is evidence and how is it used by forensic scientists?What are the characteristics of a typical crime lab?
Which historical forensic scientists laid the ground work for modern forensic science?
What is the importance of
Locard’s
Exchange Principle?Slide3
ESSENTIAL QUESTIONS
What is the basic methodology used by forensic scientists?What are the steps that must be followed in the pursuit of justice?What is the importance of the Federal Rules of Evidence?
What is the importance of the Frye Standard?
What is the importance of the
Daubert
Ruling?Slide4Slide5
Forensic Science is…
the application of science to those criminal and civil laws that are enforced in a criminal justice system.Criminalistics is…
the examination of physical evidenceSlide6
A forensic scientist…
is a generic term for a professional or academic specialist in a particular field. They are typically referred to as a “forensic toxicologist” or a “forensic pathologist,” etc.
A criminalist…
is the fancy word for a “lab technician” or a “crime scene investigator.”Slide7
Professional and Academic Specialties
CriminalisticsAnthropologyPsychiatry and Behavioral Science
Jurisprudence
Odontology
Engineering Sciences
Pathology/Biology
(incl. medical, entomology, botany)
Questioned Documents
Toxicology
Digital and Multimedia SciencesSlide8
Laboratory Analytical Specializations
Chemistry (incl. toxicology, paint/polymers, instrumentation)Computer Analysis
DNA Analysis
Explosives
Firearms and
Toolmarks
Audio, Video, and Image Analysis
Latent Print
Materials Analysis
(incl. mineralogy, metallurgy, elemental analysis)
Questioned Documents
Racketeering Records Analysis
Trace Evidence
(incl. anthropology, odontology, hairs, fibers)Slide9
What do they do?
A forensic scientist or criminalist’s primary job is to study the different types of evidence found at a crime scene, but s/he must also testify as an expert witness, perform scientific research and
train others
.Slide10
Criminalists use laboratories to help them examine…
EVIDENCE –anything that tends to establish or disprove a fact documentstestimony (oral or written)
exhibits
demonstrative
(models, diagrams, photographs)Slide11
Crime Laboratories
There are nearly 400 crime labs in USFederal, state, county, and municipal (local)Most function as part of a police departmentOthers fall under direction of the prosecutor or district attorney’s office
Some work with labs of the medical examiner or coroner
A few are affiliated with universities or exist as independent agencies in governmentSlide12
There is
NO national system of forensic laboratories, nor is there a mandatory process for accreditation so…there is little organization and consistency among US forensic labsSlide13
Most labs are maintained by states for regional areas
GBI has 7 regional labs; Eastern Regional Lab is located in Augusta and serves 15 countiesSlide14
FBI Crime Lab Services
Biometric Analysis (DNA and latent print analysis)Forensic Response (crime scene documentation, hazardous evidence response, photographic operations)Terrorist Explosive Device Analysis
Scientific Analysis
(counterterrorism and forensic science research, questioned documents, firearms/
toolmarks
, cryptanalysis and racketeering, trace evidence, chemistry)Slide15
GBI Crime Lab Departments
Chemistry (drug and fire debris, expert testimony, law enforcement education) Firearms (firearms and components, bullets and cartridges, distance determination tests,
toolmarks
, serial number restoration, NIBIN database)
Forensic Biology
(serological and DNA analysis for identification and individualization)
Latent Prints
(identification and comparison of fingerprints and AFIS database)
Medical Examiners
(forensic pathology)Slide16
GBI Crime Lab Departments
Operations Support (evidence receiving, entry into LIMS, evidence transport, storage/disposition of evidence)Toxicology (drugs/alcohol/poisons in human biological samples) *
Trace Evidence
(paint, plastic, hair, fiber, glass, fractured materials, general materials, gunshot residue)
Implied Consent
(breath alcohol testing program)
Quality System
(maintaining lab accreditation)Slide17
Crime Lab Statistics
~3.8 million requests for servicesMost were submitted to state labs (58%)38% of these requests were outsourced to other labs (public/private)~75% of all analyses are for controlled substances identification (33%)
, DNA from arrestees/convicts
(24%)
, and toxicology (15%)
~15% of cases are backlogged (>30 days)
most are DNA analysesSlide18
Crime Lab Statistics
Employ over 14k full-time personnelAverage salary for an analyst is ~$55k/yrCombined operating budget of ~$1.7 bil
.
Most labs perform controlled substances ID
(81%)
, latent print analysis
(63%)
, and biological analysis
(62%)
Oldest lab in world is in Lyons, France
(1910)
Oldest lab in US is LAPD
(1923)
Largest lab in world is FBI
(1932) Slide19
Federal Forensics Labs
Federal Bureau of InvestigationTerrorism, counterintelligence, cyber crime, public corruption, civil rights, organized crime, white-collar crime, violent crime, and weapons of mass destruction
HQ in Quantico, VA; 56 field offices
Operated by the Department of Justice (DOJ)Slide20
Federal Forensics Labs
Drug Enforcement AgencyDrug-related crimes
HQ in Arlington, VA; 313 field offices (domestic and foreign)
Operated by the DOJ Slide21
Federal Forensics Labs
Bureau of Alcohol, Tobacco, Firearms,
and Explosives
Crimes involving alcohol, tobacco, firearms, explosives, suspected arson, and organized crime
Forensic Science Labs in Atlanta, CA, and MD; Fire Research Lab in MD; 34 field offices (domestic and foreign)
Operated by the DOJSlide22
Federal Forensics Labs
United States Postal I
nspection
S
ervice
Crimes involving the mail
HQ in Dulles, VA
Operated by the United States Postal Service
United States Fish & Wildlife Service
Crimes against wildlife
HQ in Ashland, OR
Operated by the Department of the InteriorSlide23
Song Ci
(1248)First written account of using medicine and entomology to solve criminal casesPurkyně (1823)First
system of classification
of fingerprints
Bertillon
(1879)
Father of criminal identification
Developed the science of anthropometry—the taking of body measurements as a means of distinguishing people
Gross
(1893)
Father of criminal profiling
First instructive book focusing on human nature and the motives of a criminal
Locard
(1910)
Father of forensic science
Developed the idea of cross-transfer of evidence
Founders of
ForSciSlide24
Locard’s
Exchange Principle“Any action of an individual, and obviously the violent action constituting a crime, cannot occur without leaving a trace.”This simply means that every time you make contact with another person, place, or thing, it results in a cross-transfer of physical materials.Slide25
Criminal Justice and the Law
US Constitution is the supreme body of laws that trumps allStatutory Law (legislation)Enacted by a governmental body or agency having the power to make laws (such as Congress)
Common Law
(case law)
Made by judges
Precedents allow for consistency and predictability in how the law is appliedSlide26
Civil Law (code law)
Collection of codified statutesPrecedents are given less weightDeals with relationships between individualsMore concerned with assigning blame than with establishing intent“Preponderance of evidence” is required to convict
Criminal Justice and the LawSlide27
Criminal Law
(penal law)Body of rules that defines conduct prohibited by the state and assigns punishment for breachPunishments are related to the “guilty act” and the “guilty mind”Distinguishes between “major” and “minor” crimes“Beyond a reasonable doubt” is required to convict
Criminal Justice and the LawSlide28
Types of Crimes
A broken law is called a violation.INFRACTION “regulatory offenses”Least serious class of crimeCan be proceeded against without
the right to a jury trial and/or
indictment
Punishable by fines
Include traffic tickets/violations, jaywalking, littering, disturbing the peaceSlide29
MISDEMEANORMore serious class of crime than infraction
Punishable by 1 year or less in prison, house-arrest, probation, community service…Include DUI, vandalism, petty theft (<$500), prostitution, public intoxication, disorderly conduct, trespassing…Types of CrimesSlide30
FELONYMost serious class of crime
Punishable by more than 1 year in prison or by deathInclude kidnapping, arson, burglary, aggravated assault/battery, robbery, murder, grand theft (>$500), rape…Types of CrimesSlide31
The forensic scientist, or expert witness, has an
obligation to be an advocate for the truth, and should not take sides for either the defense or prosecution.The person who presents scientific evidence must establish credibility via credentials, background, and experience.
Criminal Justice and the LawSlide32
The Frye standard (Frye vs. US, 1923)
Frye was convicted of murder. On appeal, defendant’s counsel offered an expert witness to testify to the result of a deception (pre-polygraph) test, claiming that during the first trial, the testimony was not accepted.SCOTUS let the conviction stand and stated that scientific evidence must have gained “general acceptance” to be accepted in courtAt that time, the deception test was not “generally accepted”…Slide33
The Frye standard
Commonly called the “general acceptance” testDictates that expert opinion based on a scientific technique is admissible at trial only if the methodology or science is “generally accepted” as reliable in the field of studySlide34
Federal Rules of Evidence (1975)
To be acceptable in court, evidence must be RELEVANT; that is, it should be both MATERIAL and PROBATIVE.
Material evidence
is “of consequence to the determination of the action”
Probative evidence
has “the tendency to make a fact more or less probable than it would be without the evidence”Slide35
The Daubert standard
(Daubert vs. Merrell Dow Pharmaceuticals, 1993)Two families sued Dow claiming that childrens’ birth defects had been caused by mothers’ prescription drugsThe trial court decided that the petitioners’ experts’ testimony did not meet the Frye standard
In appeals, SCOTUS decided that the Frye Standard was no longer appropriate because of technological sophistication and deferred to the FRESlide36
The Daubert standard
The Frye standard was superseded by the Rules’ adoptionThe judge is the “gatekeeper” and must evaluate the expert’s scientific knowledge based on the following criteriaTheory or technique can be/has been testedSubject to peer-review and publicationKnown or potential error ratesTechnique standardization
Widespread acceptance within the fieldSlide37
The CSI effect
First reported in 2004 describing the effect of TV programs featuring forensic science on trial jurorsFamilies and jurors seem to expect instant answers from techniques that often take days/weeks/months to process and result in less definite conclusionsSlide38
The CSI effect
Jurors tend to expect more forensic evidence than is available or necessaryComplaint from juror that the prosecution had not dusted the lawn for fingerprintsORJurors have greater confidence in forensic evidence than is warrantedMurderer acquitted despite eyewitness testimonySlide39
Steps in Pursuing Justice
Once a crime is committed and discovered…A suspect may be identifiedPolice investigate what may have happenedInformation is collectedCrime scene is documented and searched for evidence
Info is assembled into a report for the prosecutor
Investigation ensues
If enough evidence can establish
probable cause
, then an arrest warrant is issuedSlide40
After a suspect is in police custody, s/he is…
Informed of his/her Miranda rights (required prior to interrogation) and processed (“booked”)Brought before a judge for arraignment to hear charges and enter a plea
Steps in Pursuing JusticeSlide41
After a defendant’s plea is made…
A preliminary hearing is conducted before a judgeThis is to determine whether there is enough evidence to proceed to a trialProbable cause must be established
Federal gov’t and some states may use a
grand jury
for felony cases
Defendant is not entitled to counsel
Steps in Pursuing JusticeSlide42
Pleading “not guilty by reason of insanity”…
Requires the defendant to prove the inability to “know right from wrong” at the time of the commission of the crimeIt removes the requirement to demonstrate intentSteps in Pursuing JusticeSlide43
A person is presumed innocent until proven guilty
The burden of proof rests with the prosecutionOnly 50% of all arrests lead to convictionOnly 25% of all convictions are sentenced to 1+ years in prisonSteps in Pursuing JusticeSlide44
Plea bargaining can reduce the burden on the court by allowing a defendant to plead guilty to a lesser charge and avoid a trial
90% of all cases are “pleaded down”Steps in Pursuing JusticeSlide45
Methodology
The Scientific Method does not and cannot work for the forensic sciences in its standard form because it does not work for past events, which cannot be observed, predicted or deduced from physical evidence, and cannot be tested experimentally.Slide46
Methodology
Acquire information about the incident of concern from primary witnessesAnticipate questions that others with vested interest in the incident will ask in the futureThis requires experience and imaginationSlide47
Methodology
Examine evidence with a focus on finding answers to the anticipated questionsCompare the consistency of alleged events (hypothesis as proposed by the witness statements) with evidential data, obtaining additional data from both lab and witnesses as neededSlide48
Methodology
Assess the validity of the conclusions to a reasonable degree of scientific certainty, recognizing the limitations of science