Unit 1 Introduction to Forensic Science and Evidence

Unit 1: Introduction to Forensic Science and Evidence

Forensic Science § Definition: The study and application of ______ to matters of _____.

Jobs of Forensic Scientists: § ________ & examine Evidence § Follow ________ protocols § Provide timely, accurate, and thorough _________ § ____ in court regarding results of analysis

Some Types of Forensic Scientists: § Anthropologist : _______________ § Odontologist : _______________ § Entomologist : _______________ § Pathologist : _______________ § Toxicologist : _______________ § Serologist : _______________ § Crime Scene Technician : ___________

Crime Lab Units § ____________Unit § Glass/Fibers/Soil/Impressions/ Markings § ____________ Unit § Serology (blood) § DNA Analysis & Blood Splatter § Anthropology (Human Remains) § Pathology (disease) § Odontology (teeth) § _______ Unit § Ballistics § Document Examination Unit § _________ § Toxicology § ________ § Latent _________ § Polygraph § Voiceprint Analysis § Cybertechnology § Psychiatry § __________________ § Evidence Collection

Major Crime Laboratories § _____-Federal Bureau of Investigation § Full Service § _____-Drug Enforcement Administration § Drug Investigations § _____-Alcohol Tobacco and Firearms § Firearms/Bombs § _________ § Crimes involving mail § U. S. Fish and Wildlife Service § _____________Services

What is evidence? • Definition: anything that tends to _______ or _______ a fact

Federal Rules of Evidence In order for evidence to be admissible, it must be: § _______-actually prove something § The more _____________to a suspect the more probative it is § Example: Fingerprints are more probative than fibers or glass found at the scene § _______-address an issue that is relevant to the particular crime

Admissibility of Evidence 1923 _____ v. _________ ýScientific evidence is allowed into the courtroom if it is _____________by the relevant scientific community. ý 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.

Categories of Evidence • _______ Evidence • Proves a direct fact • Examples: • Eyewitness Testimony • Surveillance Video • ____________ Evidence (aka Indirect Evidence) • _______a fact (but does not prove it directly) • Most types of evidence fall under this category • Physical and Biological Evidence • Examples: • Hair/Blood/Fingerprints/Documents/Glass/Impressions etc.

Classification of Evidence by Nature § _________—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacterial, fungal, botanical § _________—fibers, glass, soil, gunpowder, metal, mineral, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer § _________—fingerprints, footprints, shoe prints, handwriting, firearms, tire marks, tool marks, typewriting § _________—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification

Evidence Characteristics § ______—common to a group of objects or persons Fibers Shoe Prints § _________can be identified with a particular person or a single source Fingerprints Blood DNA Typing Shoe Prints

Class or Individual? § These fibers are _______ evidence; there is no way to determine if they came from this garment. § The large piece of glass fits exactly to the bottle; it is _________ evidence.

Eyewitness Testimony (___________ Evidence) Statement under oath by a _____________

Expert Testimony • Testimony made by a ________ person about a scientific, technical, or professional issue. • Effectiveness Depends On: • Their _______ level • Their _______ • How well they __________ • Cannot be hearsay • _________information • I heard that he…

Discussion Questions 1. Did everyone answer all of the questions correctly? 2. Did everyone have the same answers? If not, why? 3. Did you do better with practice? 4. Do you think your observations changed when you were distracted? 5. Would your answers have been good enough to testify in court?

Problems with Testimonial Evidence

Observations by Witnesses Affected By: • _________ states (stress level) • More stress = Less _____ • _______ • Ulterior Motives • Interrogation/Questioning Tactics Used • ____

The Innocence Project • Barry C. Scheck and Peter J. Neufeld at the Benjamin N. Cardozo School of Law, starting in 1992, use DNA to examine post-conviction cases. • The project has found that up to _____% of the wrongful convictions they discovered were due to faulty eyewitness identifications. 19

Original Composite Sketch of Cotton Bobby Poole: Actually committed rape Ronald Cotton: Falsely convicted of rape

Value of Physical Evidence § Generally more ________ than testimonial § Can prove that a crime has been ________ § Can corroborate or ______ testimony § Can link a suspect with a victim or with a _________ § Can establish the _____ of persons associated with a crime § Can allow reconstruction of events of a crime A forensic scientist will compare the questioned or unknown sample with a sample of known origin (control sample).

Types of Physical Evidence § ________ Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene § ________ Evidence—produced by direct contact between a person and an object or between two objects § ________ Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event § ________ Evidence—produced by contact between person(s) or object(s), or between person(s) and person(s) § ________ Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings

Examples of Transient Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene § ______—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke § ________—surroundings, car hood, coffee, water in a bathtub, cadaver § ________ and indentations—footprints, teeth marks in perishable foods, tire marks on certain surfaces § _________-Tool marks

Examples of Pattern Evidence—most are in the form of imprints, indentations, striations, markings, fractures or deposits. § § § _____spatter _____ fracture _____ burn pattern Furniture position Projectile trajectory _____marks or skid marks § Clothing or article distribution § _________residue § Material damage § ______ position § Tool marks § Modus operandi (how they did it)

Examples of Conditional Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event § _____—headlight, lighting conditions § Smoke—color, direction of travel, density, odor § _____—color and direction of the flames, speed of spread, temperature and condition of fire § Location—of injuries or wounds, of bloodstains, of the victim’s vehicle, of weapons or cartridge cases, of broken glass § ______—doors locked or unlocked, windows opened or closed, radio off or on (station), odometer mileage § Body—position, types of wounds; rigor mortis § ______—condition of furniture, doors and windows, any disturbance or signs of a struggle

Examples of Transfer Evidence Locard’s Principle: the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence • _____/Fibers • Fingerprints • _______ (due to contact---not from wounds) • _______/Impressions • Paint/Chemicals • Body ______

Examples of Associative Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings § __________ Cards § Security Camera Footage § _______ § Personal Belongings § ______ etc…

COLLECTING AND PACKAGING EVIDENCE § __________should be designated as the evidence collector to ensure that the evidence is collected consistently § Each item must be placed in a ________ container, sealed, and labeled § Most fragile is collected and packaged _____ § Different types of evidence require specific or special collection and packaging techniques § The body is the property of the _______or ________. The collection of evidence on the body is done by that department § Should also collect ________ from a known suspect or victim to compare to unknown evidence from the crime scene.

PACKAGING • Most items should be packaged in a primary container and then placed inside a secondary one. • These are then placed inside other containers such as paper bags, plastic bags, canisters, packets and envelopes depending on the type and size of the evidence. • Blood evidence should be packaged to avoid ________ • Never in ________-always in paper or sealed test tube • Arson evidence should be in an _______ container • Prevents ________ of possible fume evidence • Glass evidence should be packaged in a ____ container to avoid _____

CHAIN OF CUSTODY • There must be a __________of all people who have had possession of an item of evidence. • Without this, evidence may not be admissible in court. § The evidence container must be marked for ___________ § The collector’s _______ should be placed on the ______ § If evidence is turned over to another person, the transfer must be recorded.

THE CRIME SCENE • A crime scene is __________evidence can be found that is associated with a case • ________Crime Scene- where crime was committed • ________ Crime Scene- evidence found in a place where crime was not committed • Example: Where the victim was murdered is the primary crime scene, where the perpetrator moved the body after is the secondary crime scene

CRIME SCENE TEAM § A group of professional investigators, each trained in a variety of special disciplines. § Team Members § ________Police Officer on the scene § ________ (if necessary) § _______________(if necessary) § ________and/or Field Evidence Technician § Lab Experts

FIRST OFFICER ON THE SCENE • A _______ the crime scene and assist those hurt • D _______ the witness • A _______ the perpetrator • P _______ the crime scene • T _______

PROCESSING A CRIME SCENE § ______ and secure the scene § ______ the scene § Search for _________ § Collect and package evidence, maintaining the __________ § Submit evidence to the _______

DOCUMENTATION § _______—date and time, description of the location, weather and environmental conditions, description of the crime, location of the evidence relative to other key points, the names of all people involved, modifications that have occurred and other relevant information § _______—photos of scene and surroundings, mid-range to close-up photos with various angles of each piece of evidence, photos as viewed by any witnesses. § _______—inclusion of date, time, scale, reference points, distance measurements, names of investigators, victims, suspects, and a legend (key) § _______—allows narration (non-subjective) to be included

SEARCH METHODS § _______method—best in large, outdoor scenes § _____ method—basically a double-line search; effective, but time-consuming § _____ method—most effective in houses or buildings; teams are assigned small zones for searching § _______method—best on small, circular crime scenes § _____method—may move inward or outward; best used where there are no physical barriers

CRIME SCENE SKETCHES 4358 Rockledge Dr, St. Louis, Mo. Date: August 14, 2005 Time: 11: 35 am Homicide Ann Wilson -Drawn to ______ -All _______ is labeled -_________ are given -Sketch Information Recorded

Step 1: Draw a rough outline of the area- include windows (represented by the rectangles) and doors (represented by openings in the outline) Step 2: Measure the room or space in which the crime occurred. Label the dimensions on the sketch

Step 3: Sketch in the furniture and location of evidence using basic shapes Step 4: Label each item in the diagram with a number or letter, then write the name in a key.

Step 5: Label the diagram with the date, time, location, and victim’s name (if known) • Note: An unknown victim is commonly given the name of John Doe or Jane Doe Step 6: MEASURING FROM FIXED POINTS A. B. Make two measurements from fixed (not moveable) points to each piece of evidence Draw a line to indicate the points you measured and put in the measurement -Make sure to label the fixed point and the piece of evidence you were measuring the distance between