Types of Evidence

Types of Evidence

Lesson 1 – Types of Evidence • Essential Questions: • What are the different types of evidence? • Vocabulary: Evidence, testimonial evidence, physical evidence, indirect evidence, circumstantial evidence, questioned or unknown sample, known sample, control sample, individual evidence, class evidence

Testimonial evidenceis a statement made under oath;also known as direct evidence or prima facie evidence. Physical evidence is any object or material that is relevant in a crime; also known as indirect evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, toolmarks, impressions, glass. Classification of Evidence

Factors that affect accuracy: Nature of the offense and the situation in which the crime is observed Characteristics of the witness Manner in which the information is retrieved Additional factors: Witness’s prior relationship with the accused Length of time between the offense and the identification Any prior identification or failure to identify the defendant Any prior identification of a person other than the defendant by the eyewitness Reliability of Eyewitness

Eyewitness A police composite may be developed from the witness testimony by a computer program or forensic artist. FACES—a composite program by InterQuest

Is generally more reliable than testimonial evidence Can prove that a crime has been committed Can corroborate or refute testimony Can link a suspect with a victim or with a crime scene Can establish the identity of persons associated with a crime Can allow reconstruction of events of a crime Physical Evidence As a result of the influences on eyewitness memory, physical evidence becomes critical.

Physical evidence can be used to answer questions about: What took place at a crime scene The number of people involved The sequence of events Reconstruction A forensic scientist compares the questioned or unknown sample from the crime scene with a sample of known origin.

Transient evidence is temporary; easily changed or lost; usually observed by the first officer at the scene. Pattern evidenceisproduced by direct contact between a person and an object or between two objects. Conditional evidenceisproduced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event. Transfer evidence is produced by contact between person(s) and object(s), or between person(s) and person(s). Associative evidence is something that may associate a victim or suspect with a scene or with each other; e.g., personal belongings. —Henry C. Lee and Jerry Labriola, Famous Crimes Revisited, 2001 Types of Physical Evidence

Examples of Transient Evidence Odor—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke Temperature—surroundings, car hood, coffee, water in a bathtub, cadaver Imprints and indentations— footprints, teeth marks in perishable foods, tire marks on certain surfaces

Pattern evidence—mostly in the form of imprints, indentations, striations, markings, fractures, or deposits Clothing or article distribution Gunpowder residue Material damage Body position Toolmarks Modus operandi Examples of Pattern Evidence • Blood spatter • Glass fracture • Fire burn pattern • Furniture position • Projectile trajectory • Tire marks or skid marks

Light—headlight, lighting conditions, lights on or off Smoke—color, direction of travel, density, odor Fire—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 Vehicles—doors locked or unlocked, windows opened or closed, radio off or on, odometer mileage Body—position and types of wounds; rigor, livor, and algor mortis Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle Examples of Conditional Evidence

Biological—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacteria, fungi, botanical material Chemical—fibers, glass, soil, gunpowder, metals, minerals, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer Physical—fingerprints, footprints, shoeprints, handwriting, firearms, tire marks, toolmarks, typewriting Miscellaneous—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification Classification of Evidence by Nature

Evidence Characteristics Individual—can be identified with a particular person or a single source Fingerprints Blood DNA Typing Class—common to a group of objects or persons

Class vs. Individual Evidence The large piece of glass fits exactly to the bottle; it is individual evidence. These fibers are class evidence; there is no way to determine if they came from this garment.

Class vs. Individual Evidence, continued Which examples do you think could be individual evidence?

Include some or all of these seven major activities: Recognition—the ability to distinguish important evidence from unrelated material Pattern recognition Physical property observation Information analysis Field testing Preservation through the collection and proper packaging of evidence Forensic Investigations

Identification using scientific testing Physical properties Chemical properties Morphological (structural) properties Biological properties Immunological properties Comparison of class characteristics measured against those of known standards or controls; if all measurements are equal, then the two samples may be considered to have come from the same source or origin Forensic Investigations, continued

Individualization in demonstrating that the sample is unique, even among members of the same class Interpretation—giving meaning to all the information Forensic Investigations, continued • Reconstruction of the events in the case • Inductive and deductive logic • Statistical data • Pattern analysis • Results of laboratory analysis —Henry C. Lee and Jerry Labriola, Famous Crimes Revisited, 2001

Read a case investigated by the FBI. Observe the various units of their lab and read the section: “How Did They Do That?” www.fbi.gov/kids/6th12th/investigates/investigates.htm FBI Investigation

Lesson 2 – Evidence at a Crime Scene • Lesson Essential Questions: • How are the different types of evidence used to isolate, record, and search at the crime scene? • Vocabulary: Crime scene, modus operandi, accelerant

Kendall/Hunt Publishing Company The Crime Scene

Kendall/Hunt Publishing Company Authorities must prove: That a crime occurred That the person charged with the crime was responsible for the crime Top reasons for committing a crime Money Revenge Emotion—love, hate, anger Source of evidence Body Primary and/or secondary crime scene Suspect(s) Corpus Delicti“Body of the Crime”

Kendall/Hunt Publishing Company Team members First police officer on the scene Medics (if necessary) Investigator(s) Medical examiner (if necessary) Photographer and/or field evidence technician Lab experts Crime Scene Team A group of professionals trained in a variety of special disciplines

Kendall/Hunt Publishing Company Based on the scientific method, the Locard Exchange Principle, logic, and forensic techniques Involves: Recognition—scene survey, documentation, collection Identification—classification of evidence Individualization—comparison testing, evaluation, and interpretation Reconstruction—sequencing events, reporting, and presenting Crime Scene Investigation

Lesson 3 – Processing a Crime Scene • Lesson Essential Questions: • How are the different types of evidence used to isolate, record, and search at the crime scene? • Vocabulary: chain of custody

Kendall/Hunt Publishing Company Processing a Crime Scene Isolate and secure the scene Document the scene Search for evidence Collect and package evidence, maintaining the chain of custody Submit evidence to the crime lab for analysis

Kendall/Hunt Publishing Company First Officer on the Scene A Assess the crime scene and assist the injured D Detain the witness A Arrest the perpetrator P Protect the crime scene T Take notes

Kendall/Hunt Publishing Company Walk-through—performed by the crime scene investigator, the first officer, and sometimes the lead detective Purpose: Mentally prepare a reconstruction theory Note any transient or conditional evidence that could change over time Note environmental and weather conditions Note points of entry or exit, as well as paths of travel within the crime scene Record initial observations of who, what, where, when, and how Identify special needs within the crime scene for personnel, precautions, or equipment and notify superior officers or other agencies Crime Scene Survey

Kendall/Hunt Publishing Company Notes—date, 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 Photography—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 Sketches—inclusion of date; time; scale; reference points; distance measurements; names of investigators, victims, suspects; a legend (key) Videography—allows for narration (non-subjective) and different perspectives Documentation

Kendall/Hunt Publishing Company Line or strip method—best in large, outdoor scenes Grid method—basically a double-line search; effective, but time-consuming Zone method—most effective in houses or buildings; teams are assigned small zones for searching Wheel or ray method—best on small, circular crime scenes Spiral method—may move inward or outward; best used where there are no physical barriers Search Methods

Kendall/Hunt Publishing Company Crime Scene Sketch Date: August 14, 2005 Criminalist: Ann Wilson Time: 11:35 am Location: 4358 Rockledge Dr., St. Louis, Mo. N 5 ft

Kendall/Hunt Publishing Company One individual should be designated as the evidence collector to ensure that the evidence is collected, packaged, marked, sealed, and preserved in a consistent manner, maintaining the chain of custody. Each item must be placed in a separate container, sealed, and labeled. The most fragile evidence is collected and packaged first. Different types of evidence require specific or special collection and packaging techniques. The body is the property of the coroner or medical examiner; collection of evidence on the body is done by that department. Collecting and Packaging Evidence

Kendall/Hunt Publishing Company Packaging Most items should be packaged in a primary container and then placed inside a secondary one. Pill bottles, vials, manila envelopes, and plastic bags are good for most evidence. Trace evidence may be placed on a piece of paper which is then folded in a particular way called a “druggist’s fold.” These are then placed inside other containers such as paper bags, plastic bags, canisters, packets, or envelopes, depending on the type and size of the evidence.

Kendall/Hunt Publishing Company There must be a written record of all people who have had possession of an item of evidence, beginning at the time of collection. The evidence container must be marked for identification. The collector’s initials should be placed on the seal. If evidence is turned over to another person, the transfer must be recorded. Chain of Custody

Kendall/Hunt Publishing Company Stages Data collection Hypothesis formation Examination, testing, and analysis Determination of the significance of the evidence Theory formulation Crime Scene Reconstruction

Kendall/Hunt Publishing Company “The wise forensic investigator will always remember that he must bring all of his life experiences and logic to find the truth. This means common sense, informed intuition, and the courage to see things as they are. Then he must speak honestly about what it adds up to.” Investigators —Dr. Henry Lee Chief Emeritus for Scientific Services and the former Commissioner of Public Safety for the State of Connecticut

Kendall/Hunt Publishing Company A medical examiner is a medical doctor, usually a pathologist, and is appointed by the governing body of the area. There are 400 forensic pathologists throughout the U.S. A coroner is an elected official who usually has no special medical training. In four states, the coroner is a medical doctor. The Medical Examiner and the Coroner

Kendall/Hunt Publishing Company Identify the deceased Establish the time and date of death Determine a medical cause of death (the injury or disease that resulted in the person dying) Determine the mechanism of death (the physiological reason that the person died) Classify the manner of death Natural Accidental Suicide Homicide Undetermined Notify the next of kin Medical Examiner’s Responsibilities

Kendall/Hunt Publishing Company “The way I see it, being dead is not terribly far off from being on a cruise ship. Most of your time is spent lying on your back. The brain has shut down. The flesh begins to soften. Nothing much new happens, and nothing is expected of you.” —Mary Roach, Stiff, W. W. Norton & Company, 2003 The Corpse

Kendall/Hunt Publishing Company People in the News Dr. Michael M. Baden is a renowned pathologist and was the Chief Medical Examiner in New York City and for Suffolk County. Dr. Baden was on the panel that investigated the assassinations of president John F. Kennedy and Dr. Martin Luther King, Jr. He has been involved as an expert in forensic pathology in many cases of international interest, including: The remains of Tsar Nicholas of Russia and his family The Claus von Bülow murder trial Expert witness for the defense in the O. J. Simpson trial Reautopsy of Medgar Evers, civil rights leader Reexamination of the Lindbergh kidnapping and murder Autopsies of the victims of TWA Flight 800 Dr. Baden is the host of HBO’s Autopsy series and is featured on many of the crime talk shows.

Kendall/Hunt Publishing Company For additional information on crime scene investigation, check out truTV’s Crime Library: www.crimelibrary.com/criminal_mind/forensics/crimescene/5.html On Michael Baden and the autopsy: www.crimelibrary.com/criminal_mind/forensics/autopsy/1.html More Information

Types of Evidence