HOSA: Crime Scene and Death Investigation with Aysha

• Rules of Evidence

  Exclusionary rules that filter out irrelevent/prejudiced information
• Frye Standard

  New methods must be generally accepted by scientists
• Federal Rules of Evidence

  Allows expert witnesses to explain techniques in court
• Daubert Trilogy


  Judge becomes gatekeeper to determine the admissibility of evidence while following a court framework
• Direct Evidence


  Evidence that establishes something without further work (eyewitness testimony)
• Circumstantial Evidence


  Evidence that requires reasonable inferences to be drawn (DNA found at a crime scene)
• Class characteristic evidence


  Evidence that doesn't indicate a specific individual (shell casings, sneaker prints)
• Individual characteristic evidence


  Evidence that does indicate a specific individual (fingerprints, DNA)
• Associative Evidence


  Things found at the crime scene that can be matched to an exemplar (standard)
• Biological Evidence


  Human (or other) tissues used to identify a person or animal. Includes DNA testing.
• Chemical Evidence

  Includes drugs, explosive, toxicology ect...
• Trace Evidence

  Random stuff left at a crime scene and taken from a crime scene due to Locard's Exchange Principle
• Fingerprint Evidence


  Fingerprints and their identification and developments
• Impression Evidence

  Impressions on the ground caused by footwear, tires, ect...
• Firearm and Tool Mark Evidence

  Fired bullets, casings, Gun Powder Residue, impressions left by tools ect...
• Questioned Documents


  Examining documents for forgery
• Link Search


  One type of evidence leads to another ( most common)
• Grid Search

  Work horizontally and vertically across an area with large groups of volunteers (time consuming but effective)
• Zone Search

  Divide the area to be searched into zones and assign each person/team a zone (Best used in houses on search warrents).
• Wheel Search


  Spread out like spokes on a wheel from the center. (best used in a small circular crime scene, uncommon)
• Spiral Search

  Work outwards in concentric circles (Limited best used in the water)
• 4-36 hours after death


  Time frame for rigor mortis
• 12-36 hours


  Time frame for Livor Mortis
• 37 C

  Normal human body temperature
• 1.5 F per hour


  Time frame for cooling of a nude body a 20 C
• Contact gunshot

  Leaves large lacerations, blackened skin, and carboxymyglobin.
• Chemical Trauma


  Deaths resulting from drugs/poisons
• Thermal Trauma


  Deaths resulting from excessive temperatures
• Electrical Trauma

  Passage of electricity through a person
• Ventricular Fibrillation

  Quivering of the heart, can be caused by low voltage electricity
• Tetany


  Sustained contraction of the heart, can be caused by high voltage electricity
• Drowning


  Water in lungs, diatoms in bone marrow
• 300 g

  Normal heart weight?
• Cadaveric Spasm


  Forceful muscle contraction at the moment of death
• Autolysis


  When internal organs, including the brain, self loosen after death
• Adipocere


  Waxy, grey fat that occurs when bodies are in water
• Macerated


  Softening and breaking down of skin from prolonged exposure to water
• Arteriosclerosis


  Hardening of the arteries
• Myocardial Infraction


  A blockage of the heart that results in the death of heart muscle
• Epidural Hemorrhage

  Hemorrhage due to trauma between the Dura mater and the skull