Cause of Death: Strangulation and Suffocation Hidden Evidence Chapter Six February 16th, 2006
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Strangulation1. To choke2. Arrest circulation in a part, due to compression on windpipe3. Cut off blood supply to brain• May be done manually with hands• Or by using a cord• Length of rope• Wire
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Suffocation• Condition of being deprived of oxygen• Killing by depriving oxygen• May be caused by a plastic bag over head• Pillow held over face• Crushing weight on chest which stops ability to expand lungs to breathe• New York Death Metal Band from 1990
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Suffocation AKA Asphyxiation • Inability to breathe• Accidental or as an act of murder Caused by:• Physical crushing of throat• Toxic gases (CO)• Electric Shock• Drugs/medication• Trauma• Crushing injury to the chest• Compression of the chest• Injury to respiratory nerves• Diminished oxygen in environment• Drowning
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Cause of Death• Death by asphyxiation/suffocation– Air prevented from entering lungs• Death by strangulation– Blood supply cut off from reaching brain• Death by pressure on vagus nerve– Signals heart to stop beating• Death by separation of vertebrate (neck bones)– Separating spinal cord and instant death
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Death by Suffocation• Air prevented from entering lungs• Unconscious first – then death Block nose mouth or throat
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Death by Strangulation• Blood supply cut off from reaching brain Block throatand neck
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Death by Separation of Vertebrate• Separating spinal cord– Neck snaps• Instant death
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Accidental Suffocation• Child playing with a plastic bag• “Crush asphyxia” from being trapped in a crowd – unable to expand lungs• Falling rock landing on chest• Choking on food or vomit• SIDS – unexplained asphyxiation in infants• CO poisoning from faulty gas heater• Accidental drowning
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Smothering• Technically same as suffocation• Usually the term “smothering” used when breathing is physically impossible• Cannot expand lungs• Or cannot take in breath through mouth and nose• As compared to when there is a lack of oxygen – asphyxiation
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“Burking”• Burke and Hare made a living by selling bodies to teaching hospitals – Edinburgh, Scotland 1800’s• Bodies needed to be in good condition• Kneeling on victims chest• Covering mouth and nose with two hands• Effectively smothering or asphyxiating the victims
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Signs of suffocation Hemorrhaging – Excessive bleeding• In the brain• Around the eyeballs• Within/around the lungs• Eyeballs filled with excess fluid– May be “bulging”All caused by the muscles of the body trying to force breathing to occur
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Manual Strangulation• Killer using own hands around victim’s throatTwo main causes of death:• Prevents victim’s windpipe from taking in air – cannot breath• Cuts off blood supply to the brain• Victim becomes unconscious and eventually will die
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Signs of Strangulation• In order to cut off circulation attacker must bruise victim’s neck and throat• Bruises have specific shapes and positions– Approximately circular around throat– Around an inch in diameter– Fingernails digging into skin• Bruising of larynx (voice box or Adam’s apple)
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Signs of Strangulation• Bruising on the bottom of the mouth• Victim’s tongue is often trapped between teeth– Tongue may show bite marks and bruising• Hemorrhaging around eyesMay be broken bones or cartilage:• Hyoid bone (bone at base of tongue)• Windpipe and larynx
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Strangulation by Ligature• Ligature – rope or cord of some type used to wrap around neck• Pulled tight to cut off circulation• Deduce the type of ligature based on bruising patterns:– Deep and narrow – indicates narrow wire or cord was used– Shallow and broad – indicates rope, tie, belt, pantyhose, etc.
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Signs of Ligature• Obvious marks on neck• Marks are horizontal across neck• Lower on neck than hanging marks• Uniform depth and imprint across neck• Hemorrhaging– Neck muscles– Brain tissue• Cartilage of windpipe and larynx may fractured or may be intact
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Signs of Ligature• Finding the ligature at the scene– Becomes important Forensic evidence• Link ligature to victim’s bruises• Try to link ligature to attacker• Pattern of bruises may indicate attacker:– Left or right handed– Specific knots can be linked to attacker– Rough size of attacker – taller or shorter– Strength of attacker
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Hanging• Special case of ligature strangulation• Where gravity is used to put pressure on ligature around neckDamage depends on height of drop• If drop is swift– Neck muscles may be ruptured– Spine may actually be dislocated• If drop is slight – Neck may show little damage
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Signs of Hanging• Neck is compressed• Marks made by rope itself upon neck• Blood vessels are closed off so brain stops receiving blood• Larynx is always damaged• Hyoid bone is usually broken• Pupils of eyes dilated
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Signs of Hanging• Airways are also blocked so signs of asphyxia are evident• Deoxygenated blood turns blue from lack of oxygen• Blueness in lips and tongue• Tongue protrudes through lips• Face is completely pale from lack of blood supply to head
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(Brians rope mark was LOW, under adams apple, almost on his collar bone)
Fixed Noose• A hole of a set size is tied into the noose– Does not tighten • Slack in noose causes rope to be pulled upward and to one side• Leaving an inverted V mark on neck• Victim’s head lolls to opposite side• Causing rope marks to be uneven across the neck
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Running Noose• Where the weight of the body pulls the noose tight• Horizontal groove around neck• Mark from rope is even all around the circumference of the neck• All hangings the evidence from examining the rope is informative
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Hanged without clearing floor• Can be hanged without taking all weight off the floor – doorknob/furnitureShow signs of gradual asphyxiation:• Swollen face• Purple coloring• Many small (pinpoint) hemorrhages– Around eyes– Within Larynx (voice box)– Within windpipe
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Murder vs. SuicideSuicide• Rope is found untouched since death• Chair or ladder to stand on remains at sceneMurder• If body was dead before hanging occurred• If scene makes it impossible for victim to have completed the act on their own