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Pros & Cons of Testimonial Evidence

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1 Pros & Cons of Testimonial Evidence
Eyewitness Basics Pros & Cons of Testimonial Evidence Presentation developed by T. Trimpe 2006

2 What is testimonial evidence? The Bunny Effect CBS News Video
Testimonial evidence includes oral or written statements given to police as well as testimony in court by people who witnessed an event. Eyewitness accounts can be a useful tool in helping investigators with analyzing a crime scene, but are not viewed to be highly reliable. In addition, eyewitness identifications (right or wrong) can have a big influence on the outcome of an investigation or trial. People are likely to view the same scene in different ways depending on their positions, line of sight, familiarity with the area, and other factors that can interfere with a person’s ability to remember details. The Bunny Effect CBS News Video

3 Memory Challenge Directions:
You will have 30 seconds to view the next screen. Try to memorize all 20 items you see! You are NOT allowed to write anything down You CANNOT talk to anyone else.

4 Items to remember ... Neuroscience for Kids -

5 You have 2 minutes to list as many of the items as you can!
What do you remember? You have 2 minutes to list as many of the items as you can! How did you do? All 20 – Awesome 15-19 – Great 10-14 – Pretty swell 5-9 – Could be better 4 or Less – Wake up Teacher Note: Try to influence the students’ memory of the items. As they are writing down the items they remember, suggest two or three items that were not shown, such as a banana (on the info slide), a nail (goes with hammer), or pen (instead of the pencil). As you go over the correct items, ask the students if they added any of the ones you told them to remember. Tie this into the discussion (next slide) on how a person’s memory can be affected by another person.

6 Did you know? According to The Innocence Project (2008) "Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing." Still, the criminal justice system profoundly relies on eyewitness identification and testimony for investigating and prosecuting crimes (Wells & Olson, 2003). What factors affect a person’s memory and their ability to identify a suspect? Source:

7 Witness Factors Age may play a role in the accuracy of an eyewitness’ statement or identification of a suspect. Studies have shown that when a lineup contains the actual culprit, both young children and elderly perform well, but when the lineup does not contain the culprit there is a higher rate of mistaken identifications. The race of the witness may also play a role. The Cross Race Effect (CRE) is a phenomenon in which people are better at recognizing faces of their own race rather than those of other races. The use of drugs can alter a person’s ability to recall the events of a crime even after they are no longer under the influence. A person’s memory of an event can be influenced by other witnesses, investigators, and/or the media. Investigators use open-ended questioning and follow procedures for conducting line-ups to limit their influence on a witness’ memory of an event or identification of a suspect. Source:

8 Crime Scene & Suspect Factors
A crime that is extremely traumatic for an eyewitness may affect his/her recall of the event. For example, a witness confronted with a weapon tends to focus on the weapon rather than the perpetrator’s face. Someone who is able to focus on a perpetrator's face for a minute or longer will tend to have a more accurate memory than someone who saw the person for only a few seconds. Studies have shown that faces that are either highly attractive, highly unattractive, or distinctive are more likely to be accurately recognized. Simple disguises, such as hats or sunglasses, can interfere with accurate eyewitness identification. However, body piercings and tattoos increases the likelihood of an accurate identification. The time of day in which the crime occurred as well as a person’s view of the scene may affect what a he/she is able to see. In addition, a person who is familiar with the area in which the crime took place, may have a better recall of the positions of the victims or suspects. Source:

9 Crime Scene Challenge Now that your eyes and brain are warmed up, let’s test your observation skills a bit more. You will have 2 minutes to study the photograph of a crime scene on the next slide. Try to pay attention to details as you will be asked 10 questions about the crime scene! You are not allowed to write anything down until after the time is up. Ready?


11 Answer each question below.
1. What color coffee mug was in the picture? Blue Red Yellow 2. When was the deadline? Yesterday Today Tomorrow 3. What time was on the clock on the wall? : : :55 4. How many sticky notes were on the whiteboard? Four Six Eight 5. Which of the following was NOT in the picture? Stapler Trash Can Printer 6. What was the name on the plaque on the desk? Bill Brian Carl 7. What color was the victim's shirt? Black Blue Red 8. How many plants were in the picture? None One Two 9. What was the color of the marker in the desk drawer? Red Blue Green 10. Where was the book in the picture? On a box In the trash can Under the body Source:

12 Facial Composites Investigators work with sketch artists and eyewitnesses to create facial composites, or sketches of a person’s face. Today many police departments are using facial reconstruction software to help them with this task. The composite may be used internally to assist officers in identifying the suspect or used externally through local media (radio, TV, and newspaper) to solicit leads from citizens. FACES – A software program that offers many options to help you recreate a person’s facial features.

13 You will have a chance to try to create a facial composite
You will have a chance to try to create a facial composite. You will need to pay close attention to the following features: The shape of the face The shape of the jaw The shape of the eyes The shape of the nose The width of the neck The shape & protrusion of the ears The presence of facial piercing The presence of facial hair, its color, & location The presence of facial markings, such as scars or tattoos Forehead or other facial lines The presence of eyeglasses or sunglasses The length, color, & texture of the person’s hair Let's give it a try!

14 Crime Scene Processing
Forensics K. Davis Crime Scene Processing

15 Crime Scene Crime Labs “run” on physical evidence
Physical Evidence = encompasses any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator

16 Secure and Isolate Crime Scene
Remember- to be effective, evidence must be: Recognized Collected and processed properly Collector must be selective using knowledge of crime lab techniques, capabilities and limitations

17 Secure and Isolate Crime Scene
Crime labs do not solve crimes Many jurisdictions have specialized teams to conduct crime-scene searches Not all crime scenes require retrieval of physical evidence


19 Evidence Teams All evidence must be documented in its original state.
It is relatively common for one person to be responsible for two or more aspects of the search.

20 Evidence Teams Lead Investigator
Photographer and Photographic Log Recorder Sketch Preparer Crime Scene Search Recorder (Note-taker) Evidence Recorder Custodian Evidence Recovery Personnel Specialists

21 Lead Investigator the focal point of the crime scene investigation
exerts positive control of the entire crime scene operation must be able to control actions and access to the scene at all times to insure the investigative efforts are properly coordinated and that the scene is not compromised

22 Lead Investigator Assume control—insure safety of personnel and security at scene. Obtain all preliminary information from the initial responding officer(s) If necessary talk with the complainant to verify information Determine Boundaries Establish perpetrator’s path of entry and exit

23 Lead Investigator Conduct initial walk-through for purposes of making a preliminary survey, evaluating potential evidence and preparing a narrative description. Document & photograph obvious items Brief all team members relative to the scope and purpose of the search.

24 Lead Investigator Determine search patterns and make appropriate assignments. Designate command post location Insure that sufficient supplies and equipment are available for personnel. Control access to the scene and designate an individual to log everyone into the scene. Release the scene after a final survey and inventory of the evidence.

25 Photographer/ Photographic Log Recorder
entire scene (unaltered) including adjacent areas with overall, medium and close-up coverage using measurement scale when appropriate each item of evidence before it is moved to show position and location & close-ups to show detail

26 Photographer/ Photographic Log Recorder
all latent fingerprints, and other impression evidence, before lifting and casting is accomplished Prepare photographic log and photographic sketch. Photograph the scene as you left it. Videography with narration can be used to augment photography.

27 Sketch Preparer Diagram a Rough Sketch (at the scene)
Rough Sketch – a draft representation of all essential information and measurements at a crime scene.

28 Sketch Preparer – Rough Sketch
location of all objects & physical evidence related to the case legend; coordinate evidence nomenclature with Evidence Recorder/ Custodian and Evidence Recovery Personnel. accurate depiction of the dimensions showing distance measurements of items using two fixed points a compass heading designating north

29 Sketch Preparer – Rough Sketch
indicate adjacent buildings, rooms, furniture, etc., as needed Designate and label areas to be searched and advise Team Leader and all other search members of nomenclature for designated areas. Obtain appropriate assistance for taking measurements and list assistant(s) on sketch.

30 Sketch Preparer Prepare a Final Sketch (not at the scene)
Finished Sketch – A precise rendering of the crime scene, usually drawn to scale. (usually by professional draftsman)

31 Sketch Preparer -Finished Sketch
Contains all the information from the rough sketch in a concise, perfected presentation Often prepared with aid of templates and drafting tools Often completed using Computer Aided Drafting (CAD) programs



34 Crime Scene Search Recorder
Note-taking is a constant activity during the crime scene search. Should include detailed written description of scene Detailed description of evidence (location of items, time discovered, by whom, how and by whom it was packaged, etc)

35 Crime Scene Search Recorder
Notes often only written record of details to refresh one’s memory months or years later when at trial Tape recording or narrating videotape can be advantageous, but still should be transcribed into a written document

36 Evidence Recorder/ Custodian
Prepare evidence recovery log Coordinate evidence packaging and preservation Coordinate evidence nomenclature with Sketch Preparer and Evidence Recovery Personnel Receive and record all evidence Maintain chain of custody and control of evidence.

37 Evidence Recovery Personnel
Have all evidence photographed and videotaped before it is collected Keep Team Leader apprised of significant evidence located Initial and date all evidence and turn it over to the Evidence Recorder/ Custodian, after noting where the item was located. Insure that appropriate safety measures are adhered to, especially with respect to proper protective clothing, including gloves.

38 Specialists from industry, the academic community, private scientific labs Medical Examiner/Coroner- Bomb Engineer Geologist Entomologist Odontologist - Technician Surveyor - Blood Pattern Analyst Anthropologist - Crime Laboratory Examiner Computer Investigative Specialist

39 Conduct a Systematic Search
Preparation Approach Crime Scene Initiate Preliminary Survey Evaluate Physical Evidence Possibilities Document Crime Scene Conduct Systematic Search Record, Collect, & Process Physical Evidence Conduct Final Survey Release Crime Scene

40 Preparation Evaluate the current legal ramifications of crime scene searches. (e.g., search warrants) Fourth Amendment – prohibits unreasonable search and seizure When time and circumstances permit, obtain a search warrant before investigating and retrieving physical evidence at crime scene.

41 Preparation - Legal Considerations
A warrantless search may be justified in the following situations: the existence of emergency circumstances to prevent the immediate loss/destruction of evidence search of a person & property within the immediate control of the person provided it is made incident to a lawful arrest a search made by consent of the parties involved

42 Preparation - Legal Considerations
Mincey v. Arizona - the 1978 Supreme Court case that related to the impropriety of the warrantless collection of physical evidence at a homicide scene Michigan v. Tyler - the U.S. Supreme Court decision which dealt with the impropriety of the warrantless collection of physical evidence at an arson scene

43 Preparation Accumulate packaging & collection materials
Prepare paperwork needed Discuss upcoming search with team (b-4 search) Make preliminary personnel assignments Organize communication Organize a “command post”

44 Basic Premises The best search options are typically the most time consuming. You cannot over document the physical evidence. There is only one chance to perform the job properly.

45 International Association for Identification Safety Committee Guidelines
Gloves & shoe covers Liquid repellent coveralls & particle mask/ respiratory, goggles, face shield (when indicated) Be alert to sharp objects Use biohazard bags Note taking done with uncontaminated gloves No eating, drinking, smoking, etc. at crime scene Remove contaminated clothing & safety garments immediately (dispose or package for cleaning appropriately) & decontaminate with 10% bleach or antimicrobial soap.

46 First officer(s) on scene should:
If necessary render aid to the victim(s). Arrest perpetrator if present Preserve and protect area as much as possible Exclude all unauthorized personnel from scene begin recording who enters and leaves (entry log) Isolate area using ropes, tape, barricades, guards, etc.

47 Initiate a Preliminary Survey of Scene
Cautious walk-through of the scene Acquire preliminary photographs. Delineate extent of the search area Organize methods and procedures needed Determine personnel and equipment needs Identify & protect transient physical evidence. Develop a general theory of the crime Brief team

48 Evaluate Physical Evidence Possibilities
Based on type of crime, establish evidence types most likely to be encountered Insure sufficient collection & packaging equipment Concentrate on the most transient evidence first Focus first on the easily accessible areas Look for evidence of “foul play” at the scene

49 Document the Scene Documentation of a crime scene is extremely important. The Golden Rule Is; Do Not Touch, Move, Or Alter Any Evidentiary Item Until You Document The Scene. Notes Photography/Video Sketches

50 Document the Scene - Notes
Accurate & Legible Facts, observations, and statements; not conclusions or evaluations Each investigator should keep notes Purpose Assist with the preparation of your written reports. Refresh you memory during the investigation and at trial. All notes need to be preserved for court.

51 Notes Guidelines Use a bound type of notebook Write in ink
Number the pages consecutively, in advance, to avoid any subsequent allegations about removing or destroying pages. Draw a single line through any errors you may make , initial and date the error, & make corrections Try to make all entries in chronological order leaving with no blank spaces. It is a good practice to initial and date each page as you complete them.

52 Notes should include: Your assignment What you observed
People on scene, contacted, interviewed, or arrested Evidence found or recovered The conditions at the scene Methods of narrative—written, audio, video Time cleared

53 Document the Scene - Photography
Excellent means of documenting detail Should be fair and accurate, and represent the crime scene exactly as you found it Begin ASAP — plan before taking shots Photography log – include conditions, date, time, frame number, subject matter, location, etc. Overall, medium and close-up views of the scene (Do not place numbers in these pictures.)

54 Document the Scene - Photography
Use a recognized scale device & evidence # for size determination and identification (Be sure to take a picture without them in the scene as well.) Photograph/videotape evidence in place before its collection and packaging. Include areas adjacent to, the crime scene—points of entry, exits, windows, attics, etc. Photograph/videotape items, places, etc., to corroborate the statements of witnesses, victims, and suspects.

55 Document the Scene - Photography
From eye-level, when feasible, to represent the normal view. Usually supplemented by diagrams/sketches. Create a photo diagram if necessary. Prior to lifting latent fingerprints, photographs should be taken 1:1, or using appropriate scale. Videotape can be used to supplement your narrative and photographs, and video can best be used in the overall shot or documentation of the scene.

56 Prepare a Diagram/Sketch of Scene
Establishes a permanent record of items, conditions and distance/size relationships Supplement photographs Refresh your memory of the event Significant dimensions should be accurately recorded to show distance and should contain sufficient measurements and detail to be used as a model for a drawn-to-scale. Rough sketch - drawn at scene; changes may not be made once you have left the scene. Number designations on sketch should coordinate with the evidence log.

57 Prepare a Diagram/Sketch of Scene
Select a sketch technique Insure that enough room is allowed Accurate and consistent measurements must be taken before the evidence is collected. Triangulate for exact distance. Use the lowest scale on the ruler/measuring tape Record measurements on a separate piece of paper, the key or legend, rather than on the rough sketch itself. Record administrative information, such as the scale disclaimer (not drawn to scale)

58 Sketch should include:
Case number Exact location Date and Time Person preparing the sketch and all those who assisted. Compass orientation (North arrow) Key or legend containing: Evidence represented by numbers (DO NOT USE I & O) Fixed points and large objects represented by letters Measurements Direction of stairway Direction a door opens

59 Prepare a Diagram/Sketch of Scene
Do not overcrowd the sketch with nonessential items or details. The rough sketch may also be required to be produced at the trial. Remember, you must complete the rough sketch and all necessary corrections before leaving the crime scene.

60 Conduct Systematic Search
Thorough and systematic How it is searched depends on type of crime, local and size of scene, # of collectors, etc. Collect massive objects to microscopic traces (all possible carriers of trace evidence) Portable vacuum cleaners helpful


62 Conduct Systematic Search
Medical examiner may also provide evidence such as: Victim’s clothing Fingernail scrapings Head and public hairs Blood (for DNA typing) Vaginal, anal, and oral swabs (in sex crimes) Recovered bullets from body Hand swabs from shooting victims

63 Search Patterns Strip or Lane Search Method
used for covering large or open areas line up shoulder to shoulder move slowly along examining parallel strips of terrain

64 Search Patterns Grid Search Method
variation of the strip search method best used outdoors search a strip along one axis, east to west then come back and cover the same area on a north to south axis

65 Search Patterns Zone or Sector Search Method Point to Point
area is divided into zones or sectors Each person is assigned a sector to do a thorough search. Point to Point Even though this is not very systematic, it can be used in small confined areas.

66 Search Patterns Spiral or Circular Search used for outdoor scenes
usually conducted by a single searcher who walks in a slightly decreasing, less-than-concentric circle from the outermost boundary towards the center process should not be reversed can be used for underwater searches.

67 Search Patterns Clockwise – Counter Clockwise – Inside
involves two agents working together The first agent would search in a clockwise direction searching the area from the waist up to the ceiling The second agent would search counter clockwise waist down to floor Once you have completed one pass, reverse roles and repeat the process.

68 Record & Collect Physical Evidence
Each class of evidentiary items is handled differently. Remember that there is no set procedure applicable to every case, only general guidelines to be followed in most cases. Photograph or videotape all items before collection and enter notations in photographic or video log (remember—use scale when necessary). Mark evidence locations on the diagram/sketch.

69 Collect & Process Evidence
Maintain evidence in original condition if possible Prevent change which can arise from contamination, breakage, evaporation, accidental scratching or bending, or loss through improper or careless packaging Each different item or similar items collected at different locations must be placed in separate containers to prevent damage and/or contamination

70 Collect & Process Evidence
One of the most important principles is that evidence of a fragile nature must be collected first as it can easily be destroyed by personnel, changing environmental or other conditions. Examples of fragile evidence include: Trace materials such as hairs and fibers, Various body fluids (DNA evidence), Latent friction ridge evidence, Volatile liquids, etc.

71 Collect & Process Evidence
Each item of evidence collected should be marked for identification. place your initials, date, item number, and case number on the item, package, or tag as appropriate seal container and place your initials and date along the seal edges where they make contact with the packaging If there is a possibility that you could destroy evidence, mark on the container you put the item in. If you are unsure of what type of packaging to use, and the item is not a liquid or very wet, place the item in a porous container.

72 Complete Evidence Log Have at least two persons:
See evidence in place before collection Observe it being recovered Mark the evidence (mark item itself whenever feasible) Count currency, or inventory valuables seized as evidence/contraband. Place identifying marks on evidence containers, e.g. date, time, case number, name of agent, etc.

73 Complete Evidence Log Do not handle evidence excessively after recovery. Seal all evidence containers at the crime scene. Do not guess on packaging requirements—different types of evidence can necessitate different containers. Do not forget entrance and exit areas at scene for potential evidence.

74 Complete Evidence Log Be sure to obtain appropriate “known” standards (e.g., fiber sample from carpet). Constantly check paperwork, packaging notations and other pertinent recordings of information for possible errors, which may cause confusion or problems at a later time.

75 Obtain Controls Examination of evidence often requires comparison with known standard or control Standard/reference sample (control): physical evidence whose origin is known, such as blood or hair from a suspect that can be compared to crime-scene evidence. Substrate control – uncontaminated surface material close to an area where physical evidence has been deposited. This sample is to be used to ensure that the surface upon which a sample has been deposited does not interfere with laboratory tests. Buccal Swab – swab of inner portion of cheek; cheek cells are usually collected to determine the DNA profile of an individual.

76 Obtain Controls Quality and quantity of controls may help determine evidential value of crime-scene evidence Controls must be treated with equal care as actual evidence

77 Maintain Chain of Custody
records the movement of the evidence the “life history” of the item from the time that it was discovered until it is no longer needed essential to the admissibility of an item of evidence in judicial proceedings An item of evidence, whose custody cannot be firmly established from the time of discovery to court presentation, may not be admitted no matter how potentially informative it could be.

78 Maintain Chain of Custody
Mark each item for identification (without compromising sample) Enter the item on the chain of custody Ensure the item number is the same as entered on your evidence log, the item, and the sketch. Properly record the chain of custody information at every stage of evidence handling or transfer from one person to another & document the reason for transfer.

79 Maintain Chain of Custody
Store the items in a secured vault or special room with limited access. Limit the number of personnel who are involved in the movement of the evidence. The longer the chain the more potential there will be for a weak link to exist.

80 Submit Evidence to Lab Can be by personal delivery or by mail shipment
Method of transmittal is determined by: the distance the submitting agency must travel to the laboratory the urgency of the case Must be accompanied by evidence submission forms List of tests to be performed on each item List of items submitted

81 Conduct a Final Survey Critical review of all aspects of the search
Discuss search jointly with all personnel for completeness. Double-check documentation to detect inadvertent errors. Check to insure all evidence is accounted for before departing scene. Ensure all equipment used in the search is gathered. Make sure possible hiding places or difficult access areas have not been overlooked in detailed search.

82 Release Crime Scene Release is accomplished only after completion of the final survey. At minimum documentation should be made of: Time and date of release To whom released By whom released Ensure that appropriate inventory has been provided, as necessary considering legal requirements, to person to whom scene is released.

83 Release Crime Scene Once the scene has been formally released, re-entry may require an additional warrant. Evidence recovered during a re-entry may not have the integrity as that recovered during the original search. Only the person-in-charge should have the authority to release the scene. Consider the need to have certain specialties observe the scene before it is released (e.g., blood pattern analysis, ME).

84 The Trial of the Century
O.J. Simpson was a NFL football legend. He is now famous for having been tried for the murder of ex-wife Nicole Brown Simpson & her friend Ronald Goldman in 1994. He was acquitted in criminal court after a lengthy, highly publicized trial.

85 What went wrong? Upon arrival, police found evidence of blood and entered the Simpson home without a search warrant (permissible - emergency situation). HOWEVER, the police collected a pair of blood-stained gloves during their search. Collection of evidence without proper warrants became the key argument used by Simpson’s legal team & ultimately led to his acquittal.

86 What was learned? If forensic evidence is to be admissible in court, the highest professional standards must be used at the crime scene! He was found liable for their deaths in civil court, but has yet to pay the $33.5 million judgment. Calif law…..pensions cannot be used to pay out a judgment Florida law assets cannot be seized to pay out a judgment

87 Video: Crime Scene Clean-up

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