2009©Forensic Science Today1 Crime Scenes Physical Evidence- Any object that can establish that a crime has been committed or can link a crime and its victim or its perpetrator

2009©Forensic Science Today2 Secure the Scene Why? -to keep others out -to prevent alteration & destruction How? –tape off area large enough to contain all possible evidence (w/in reason)

2009©Forensic Science Today3 Responsibilities of First Responder Obtain medical assistance if necessary Arrest the perpetrator Preserve and protect the area Exclude all unauthorized personnel from the scene

2009©Forensic Science Today4 Search the Scene Record -take notes, photos and sketch (Do not alter the scene!) Points of entry and exit must be noted. Choose a method -systematic Gloves Quadrant search

2009©Forensic Science Today5 Photographing the Scene Scene must be in unaltered condition for photos to be admissible in court. Necessary movement of evidence must be noted in the report but cannot be reintroduced as a “staged” photo. Take overview scenes of entire area and adjacent surroundings. Include points of entry and exit

6 If a body is present, photograph the position and location relative to the entire scene. take close-ups of injuries and weapons. When appropriate to move the body, take pictures of the surface beneath the body. Include a ruler as a point of reference to document size.

2009©Forensic Science Today7 Sketches Rough sketch drawn at the scene contains an accurate depiction of the dimensions of the scene and shows the location of all object having a bearing on the case Finished sketch a precise rendering drawn to scale (CAD- computer aided drafting)

2009©Forensic Science Today8 Notes Detailed description of physical evidence including time of discovery, who discovered it, how it was discovered, and who packaged the evidence, and the disposition of the evidence. May be the only source of info for refreshing one’s memory on a cold case Tape recording and video recording is useful.

2009©Forensic Science Today9 Chapter 2 The Crime Scene Part II Objectives: Describe proper procedures for conducting a systematic search of a crime scene for physical evidence Describe proper techniques for packaging evidence Define the concept of Chain of Custody

2009©Forensic Science Today10 Goals of the Crime Scene Search Provides information on the “Corpus Delicti” (“body of the crime”) Provides information on the “Modus Operandi” (“mode of operation” or MO) Links a suspect with a victim Links a person with a crime scene Disproves or supports and alibi or witness’s testimony Identifies a suspect Provides investigative leads Identifies unknown substances

2009©Forensic Science Today11 Theories of Crime Scene Searches Linkage Theory: The case can be solved if investigators can establish links between physical evidence and the victim, crime scene and/or suspect Transfer Theory: Based on Locard’s Theory of Exchange Whenever you leave a location, you leave something behind (hair, soil from shoes, etc.) and take something with you. (fibers)

2009©Forensic Science Today12 Conduct a thorough search Organization and experience are critical- chief officer to assign duties View scene as a whole initially (look for missing items as well as evidence) Consider the possibility of a primary or secondary crime scene Scene must be guarded at all times until it is released. Scene MUST remain intact unless absolutely necessary. Document any changes. (e.g. removal of evidence, closing a window)

2009©Forensic Science Today13 Search Methods (see p. 41) Strip or line search Useful in large, outdoor areas Grid method- more thorough version of line search Spiral method- Danger- evidence may be destroyed if investigators initially walk to the center to begin search Zone search Useful in indoor searches Wheel method Used in special situations, not in large areas Link method Used in conjunction with the above

2009©Forensic Science Today14 Experience Rules Good Crime scene investigators “expect the unexpected” and “leave no stone unturned”

2009©Forensic Science Today15 Types of Searches

2009©Forensic Science Today16 Notetaking Date/Time of Arrival Name Address/Description Weather Conditions Log of All Activities

2009©Forensic Science Today17 Sketch the Scene All evidence found Measurements, 2 from fixed points Orientation & Direction (North directional marker) Labels for representing evidence

2009©Forensic Science Today18 Measure Each Piece of Evidence From two fixed points or using triangulation.

2009©Forensic Science Today19 Photograph Overview Rooms or areas near the scene Entry/Exit Physical evidence Close-ups and perspective

2009©Forensic Science Today20 Collection Separate containers Gloves Label outside of container Seal the container

2009©Forensic Science Today21 From the Body Collect *hair and fiber *clothing *blood sample *bullets *hand swabs from shooting victims for GSR analysis *fingernail scrapings *oral, anal and vaginal swabs in sexual assaults *organ samples for possible testing

2009©Forensic Science Today22 Containers – See appendix I pp In order to prevent loss or damage: *Appropriate size * Appropriate type Suitable for most trace evidence

2009©Forensic Science Today23 Container Types Body Fluids –in porous container to avoid formation of mold or mildew Glass or other breakables –in rigid container Metal objects –in rigid container Bloodstained materials should not be stored in air-tight containers

2009©Forensic Science Today24 More Container Types Trace Evidence –in Druggist fold w/ container that allows no leakage Arson Evidence- in nonporous & unbreakable container

2009©Forensic Science Today25 Labeling On outside of container place… *Name *date *time *description of evidence Tamper-proof seal is required

2009©Forensic Science Today26 Seal on the container Cover opening w/ seal Write on seal *initials *date Maintain proper Chain of Custody

2009©Forensic Science Today27 Obtain Standard/Reference Samples For comparison Examples may include paint from a suspect vehicle, hair Bloodstained evidence must include a buccal swab (swab from the inner portion of cheek of crime-scene participants for DNA comparison) Substrate Control-materials close to areas where evidence has been deposited (Arson cases, bloodstains)

2009©Forensic Science Today28 Chain of Custody Who… When… What… Where… Why maintain chain of custody?

2009©Forensic Science Today29 Maintain Chain of Custody Transfer of evidence must be recorded Everyone involved in the collection and transportation of evidence may be requested to testify To avoid confusion To retain complete control of evidence at all times

2009©Forensic Science Today30 Submit Evidence to Lab See p. 48 Fig 2-8 for Evidence submission form Mail is acceptable if packaging is appropriate Each item packaged separately Each item assigned an identifying number or letter referenced on form

2009©Forensic Science Today31 Release the Scene Reasonable time Check walk through Record *released to… *date/time Warrant

2009©Forensic Science Today32 Crime Scene Safety PPE includes gloves and coverall gowns; surgical masks and protective eyewear is required when handling bodily fluids or attending an autopsy. Avoid contact with biohazards (i.e. blood and bodily fluids) OSHA requires law enforcement agencies to offer Hepatitis B vaccines for employees at no cost Be wary of sharp objects No smoking, drinking or eating or application of make-up Label evidence contaminated with body fluids as “Caution-Potential AIDS (or Hepatitis) Case Contact authorities when dealing with explosives Clean hands with diluted bleach solution, soap and water. Discard contaminated shoes and clothing.

2009©Forensic Science Today33 Legal Considerations Searches must conform to the Fourth Amendment The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizure, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

2009©Forensic Science Today34 Warrants Probable cause Warrantless searches Consent given Evidence in immediate danger of loss Emergency circumstances exist Someone being lawfully arrested