Forensic Science

Forensic Science

Forensic Science SFS1. Obtain, evaluate, and communicate information to properly conduct a forensic investigation of a crime scene. a. Construct an explanation of how scientific forensic techniques used in collecting and submitting evidence for admissibility in court have evolved over time. (Clarification statement: Emphasis is on Locards Exchange Principle, Frye standard, Daubert ruling) ESSENTIAL QUESTIONS

1. What is forensic science? 2. What is evidence and how is it used by forensic scientists? 3. What are the characteristics of a typical crime lab? 4. Which historical forensic scientists laid the groundwork for modern forensic science? 5. What is the importance of Locards Exchange Principle? ESSENTIAL QUESTIONS

6. What is the basic methodology used by forensic scientists? 7. What are the steps that must be followed in the pursuit of justice? 8. What is the importance of the Federal Rules of Evidence? 9. What is the importance of the Frye Standard? 10.What is the importance of the Daubert Ruling?

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 evidence 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. Professional and Academic Specialties Criminalistics Anthropology

Psychiatry and Behavioral Science Jurisprudence Odontology Engineering Sciences Pathology/Biology (incl. medical, entomology, botany) Questioned Documents Toxicology Digital and Multimedia Sciences 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)

What do they do? A forensic scientist or criminalists 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. Criminalists use laboratories to help them examine EVIDENCE

anything that tends to establish or disprove a fact documents testimony (oral or written) exhibits demonstrative (models, diagrams, photographs) Crime Laboratories There are nearly 400 crime labs in US Federal, state, county, and municipal (local) Most function as part of a police department

Others fall under direction of the prosecutor or district attorneys office Some work with labs of the medical examiner or coroner A few are affiliated with universities or exist as independent agencies in government 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 labs Most labs are maintained by states for regional areas GBI Division of Forensic Sciences has 7 regional labs; Eastern Regional Lab is located in Augusta and serves 15 counties 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) 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) 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) Crime Lab Statistics ~3.8 million requests for services Most 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 analyses Crime Lab Statistics Employ over 14k full-time personnel Average salary for an analyst is ~$55k/yr

Combined 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) Federal Forensics Labs Federal Bureau of Investigation

Terrorism, 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) Federal Forensics Labs Drug Enforcement Agency Drug-related crimes HQ in Arlington, VA; 313 field offices

(domestic and foreign) Operated by the DOJ 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 DOJ Federal Forensics Labs United States Postal Inspection Service 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 Interior Song Ci (1248) Founders of ForSci First written account of using medicine and entomology to solve criminal cases Purkyn (1823)

First system of classification of fingerprints Bertillon (1879) Father of criminal identification Developed the science of anthropometrythe 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 Locards 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. Criminal Justice and the Law US Constitution is the supreme body of laws that trumps all Statutory 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 applied Criminal Justice and the Law Civil Cases Derived from common law Deals with relationships between individuals Person (Plaintiff) vs. Person (Defendant) More concerned with assigning blame than

with establishing intent Preponderance of evidence is required to convict Criminal Justice and the Law Criminal Cases Derived from statutory law Body of rules that defines conduct prohibited by the state and assigns punishment for breach State (Prosecution) vs. Person (Defendant)

Punishments are related to the guilty act and the guilty mind Beyond a reasonable doubt is required to convict Types of Crimes A broken law is called a violation. INFRACTION regulatory offenses Least serious class of crime Can be proceeded against without the right to a jury trial and/or indictment

Punishable by fines Include traffic tickets/violations, jaywalking, littering, disturbing the peace Types of Crimes MISDEMEANOR More serious class of crime than infraction Punishable by 1 year or less in prison, housearrest, probation, community service Include DUI, vandalism, petty theft (<$500), prostitution, public intoxication, disorderly conduct, trespassing

Types of Crimes FELONY Most serious class of crime Punishable by more than 1 year in prison or by death Include kidnapping, arson, burglary, aggravated assault/battery, robbery, murder, grand theft (>$500), rape Criminal Justice and the Law

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. The Frye standard (Frye vs. US, 1923) Frye was convicted of murder. On appeal,

defendants 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 court At that time, the deception test was not generally accepted The Frye standard

Commonly called the general acceptance test Dictates 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 study 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 a fact 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 The Daubert standard (Daubert vs. Merrell Dow Pharmaceuticals, 1993) Two families sued Dow claiming that children's birth defects had been caused

by mothers prescription drugs The 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 FRE The Daubert standard The Frye standard was superseded by the

Rules adoption The judge is the gatekeeper and must evaluate the experts scientific knowledge based on the following criteria Theory or technique can be/has been tested

Subject to peer-review and publication Known or potential error rates Technique standardization Widespread acceptance within the field The CSI effect First reported in 2004 describing the effect of TV programs featuring forensic science on trial jurors Families and jurors seem to expect instant answers from techniques that often take

days/weeks/months to process and result in less definite conclusions The CSI effect Jurors tend to expect more forensic evidence than is available or necessary Complaint from juror that the prosecution had not dusted the lawn for fingerprints OR Jurors have greater confidence in forensic

evidence than is warranted Murderer acquitted despite eyewitness testimony Steps in Pursuing Justice Once a crime is committed and discovered Police investigate what may have happened Information is collected Crime 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 indictment may be issued, resulting in the arrest of a suspect Grand jury may be used in serious felony cases Steps in Pursuing Justice 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 Justice If a defendants plea is not guilty A preliminary hearing is conducted before a judge This is to determine whether there is enough evidence to proceed to a trial Probable cause must be established

Steps in Pursuing Justice 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 crime It removes the requirement to demonstrate intent Steps in Pursuing Justice

A person is presumed innocent until proven guilty The burden of proof rests with the prosecution Only 50% of all arrests lead to conviction Only 25% of all convictions are sentenced to 1+ years in prison Steps in Pursuing Justice 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 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. Methodology 1. Acquire information about the incident of concern from primary witnesses 2. Anticipate questions that others with vested interest in the incident will ask in the future This requires experience and

imagination Methodology 3. Examine evidence with a focus on finding answers to the anticipated questions 4. Compare the consistency of alleged events (hypothesis as proposed by the witness statements) with evidential data, obtaining additional data from both lab and witnesses as

needed Methodology 5. Assess the validity of the conclusions to a reasonable degree of scientific certainty, recognizing the limitations of science

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