Forensic Medicine Flashcards
- ______crime-solving: relating to the application of science to decide questions arising from crime or litigation
•[Mid-17th century. From Latin 2. ____ “of legal proceedings,” originally “of the forum (as a place of discussion),”
- fo·ren·sic
2. forensis
Branch of medical science which deals with the application of medical knowledge to elucidate legal problems
•“Forum”
•All branches of medicine can have forensic aspect.
•The main objective is the TRUTH based on the evidence.
Forensic medicine
= in 1975 found bamboo pieces from Qin dynasty dating 220BC w/c had info on rules and regulations for examining injuries
China
= Code of Hammurabi (king of Babylon) w/c dates 2200BC about rights and duties of physicians including malpractice
Iraq
= laws of Manu dating 10BC about competencies of witnesses in courts
India
= papyri dating 4th century AD about forensic medical examination or investigation
Roman Egypt
FUNCTIONS OF MEDICO-LEGAL DIVISION
AUTOPSY •PHYSICAL EXAMINATION •ANTHROPOLOGY •ODONTOLOGY •HISTOPATHOLOGY •SEROLOGY •DNA •SOCO •COURT DUTY •RESEARCH, LECTURES
- Conducts physical examination on living persons (7 working days)
- Conducts genital examination to determine sexual abuse and time of infliction of injury.
- Conducts physical examination persons involved in physical injury cases to determine the presence and extent of injuries
- Conducts autopsies to determine the exact cause, manner, mechanism and approximate time of death. (7 working days)
- Conducts exhumation to determine the cause of death and identity of persons
Medico-Legal Officer
•Examination of human dentition and applying the characteristics in identification of individuals (5 working days)
Odontological Examination
•To determine the cause of death thru microscopic tissue examination (28 workings days)
Histopathological Examination
- To determine presence of human blood,type and characteristics
- To determine the presence of semen (4 working days)
Serological Examination
- Conducts SOCO processing to identify, collect, examine, and present before the courts evidence at the crime scene
- Conducts Field Laboratory Work
- Appears and testifies in court as expert witness
- Lectures to different police/military institutions, government agencies and private/public schools
- Orients and trains new personnel and on-the-job trainees on the mission, functions and capabilities of the division;
Medico-Legal Officer
MEDICO-LEGAL DEATHS
•1. VIOLENT DEATHS -accidents - suicides - homicides •2. SUSPICIOUS DEATHS •3. SUDDEN UNEXPECTED DEATHS/MEDICALLY UNEXPLAINED DEATHS •4. UNATTENDED DEATHS •5. DEATH IN CUSTODY •6. POISONING •7. POSSIBLE THREAT TO PUBLIC HEALTH •8. DEATH RELATED TO EMPLOYMENT •9. DEATH ASSOCIATED TO THERAPEUTIC AND DIAGNOSTIC PROCEDURE •10. UNLAWFUL TERMINATION OF PREGNANCY •11. BODIES TO BE CREMATED •12. UNCLAIMED CADAVERS •13. SUSPICIOUS CHILD DEATHS •14. UNEXPECTED DEATH OF PUBLIC OFFICIAL
Five categories of medico-legal cases
memorize
- Violent deaths
- Suspicious deaths
- Sudden and unexpected
- Unattended death
- Death in custody
Objectives of medico-legal examination of a body are:
- To determine the cause of death
- To determine the manner of death
- Estimate the time of death
- To document all findings
- To determine or to exclude other factors
- To collect trace evidence in criminal cases
- To positively identify a body
- To testify in court
- Interpret findings
•Comprehensive study of a dead body, performed by a trained physician employing recognized dissection procedure and techniques.
•Removal of tissues for further examination
read!
Autopsies
Kinds of autopsies
ok
- Hospital or non-official autopsy
* Medico-legal or official autopsy
Kinds of autopsies
–Consent from relatives
•Spouse, descendants of the nearest degree, ascendants of nearest degree, brothers and sisters (decreasing order)
A. HOSPITAL/ NON-OFFICIAL AUTOPSY
Purpose:
•Determine cause of death
•Provide clinical correlation of diagnosis and clinical symptoms
•Determine the effectiveness of therapy
•Study natural course of the disease process
•Educating students and physicians
HOSPITAL/ NON-OFFICIAL AUTOPSY
–Dead body belongs to the state for protection of public interest
•All that needs to be turned over to the next of kin would be burial of the deceased
MEDICO-LEGAL or OFFICIAL AUTOPSY
–Purpose:
•Determine cause, manner and time of death
•Recovering, identifying and preserving evidentiary material
•Providing interpretation and correlation of facts and circumstances related to death
•Providing a factual, objective medical report for law enforcement, prosecution and defense agencies
•Separating death due to disease and death due to external cause
MEDICO-LEGAL or OFFICIAL AUTOPSY
Starts in the morgue Focuses on the internal findings Determines cause of death Determines prognosis ok
Hospital Autopsy
- Starts in the crime scene
- Focuses on the external and internal findings
- Determines cause / manner/ mechanism of death
- Clothes included in the autopsy
- R.I.P. of evidence
- Determines identity
ok
Forensic/Medico-legal Autopsy
When shall an autopsy be performed on a dead body
SEC 98 (B) P.D. 856, Code of Sanitation
ok
- Whenever required by special laws
- Upon order of a competent court, a mayor and a provincial or city fiscal
- Upon written request of police authorities
- Whenever the solicitor general, provincial or city fiscal as authorized by existing laws shall deem it necessary to take possession of the remains and determine cause of death
Persons who are authorized to perform autopsies and dissections
repeat
Health officers
•Medical officers of the law enforcement agencies
•Members of the medical staff of accredited hospitals
Disease or injury that results in the individual dying.
ok
Cause, Manner, Mechanism
Cause of Death:
How the cause of death came about.
repeat
Manner of Death
a. Suicide
b. Homicide
c. Accident
d. Natural
e. Undetermined
physiological derangement.
ok
- Mechanism of Death:
- Circumstances
- witnesses
- investigators
- history
- the scene
- medical records - Examination of Body
- search!
- Laboratory test
- ballistics
- toxicology
- paraffin
3 steps in medico-legal investigation
- Document first- photos, sketches
- Minimal handling of the body
- Protect the hands- use paper bag
- Wrap the body in white clean sheet/ cadaver bag
- Encircle the injection sites
- In the hospital, don’t remove tubes
- Document the location, number of injuries
- Medical records/ procedures done must accompany the body
Con’t
9. In the morgue, must log the case, include
Who brought the body, what time, who received it
10. Don’t wash the body! Examining the clothing is an important part of autopsy.
11. Photo before and after cleaning the body.
Re-examine after cleaning.
12. X-ray: GSW and child abuse
13. Photo with ruler each injury.
14. Internal examination-autopsy proper
15. Lab test: toxicology, histology, neuropathology,
microbiology, serology, ballistics
16. Lastly, fingerprint and palm print
ok
Handling of bodies
– age/sex, race, physique, height, nourishment
–Congenital malformations
–Brief description of clothing
–General description of body state
•Degree of rigor/livor mortis
•Hair (length and color), facial hair, alopecia
•Eye appearance, eye color, teeth, dental plates, scars , tattoos, old injuries unrelated to death, evidence of recent medical intervention
Autopsy Report
I. External Examination
- external and internal injuries
- GSW: assign number, location, characteristics, trajectory
- pertinent negatives
- entrance and exit
- describe the slug, location
- all bullets should be recovered
Autopsy Report
II. Evidence of Injuries
-weight of organ is important, dimensions of organs not needed.
Autopsy Report III. Internal Examination ... IV. Microscopic Examination V. Toxicology VI. Findings VII. Opinion
-Blood
-Semen
-Hair
-Tissue
-Fingernails
-Bite marks
-Saliva
ok
physical Evidence
a. Biological evidence
-clothing
-bullets
-fibers
-paint
-glass
-soil
ok
physical Evidence
B. Non-biological evidence
Manner of death that must be autopsied
1, Death by violence
- accidental death
- Sudden death of person who are apparently in good health
- suicide
Cause, Manner, Mechanism
Gunshot wound?
Stab wound?
blunt force?
ok
Cause of death
Cause, Manner, Mechanism
Massive hemorrhage?
peritonitis
septicemia
hemorrhage
mechanism of death
Physical Evidence
a. Biological evidence
B. Non-biological evidence
I. Factors used in estimating time of death
ok
- livor mortis
- rigor mortis
- algor mortis
- vitreous (eye) potassium
- stomach contents
- environmental factors
(post mortem lividity)
livor mortis
(muscle stiffening)
rigor mortis
(body temp)
algor mortis
(eye)
vitreous potassium
Philippine Criteria of Brain Death
ok
I. An individual who has sustained:
A. Irreversible cessation of circulatory and respiratory functions; or
B. Irreversible cessation of all functions of the entire brain, including the brain stem
postmortem lividity Due to settling of blood by gravity on dependent areas of body If pressed against hard surface - pale coloration is seen Reddish, purplish blue color Begins in \_\_\_mins Intensifies over time May result in post mortem petechiae Its not a contusion Livor vs contusion? ok
LIVOR MORTIS
30 mins
LIVOR MORTIS
Up to 6 hpm
Complete shifting
6-12 hpm
Incomplete shifting
Over 12 hpm
No shifting
pale coloration
lividity
Stiffening of the body after death
Due to postmortem muscle contraction
Depletion of ATP > stable complex of actin and myosin
begins within ___ hours after death
jaw>face>upper ext > lower ext
_______ – full rigor mortis
RIGOR MORTIS
2 hours
6-12 hours
RIGOR MORTIS
Lost due to decomposition
Temperate climates – persists for 36-48 hours
Warm climates – persists less than ____hours
Cold weather – persists for several days
Cadaveric spasm-rare
24 hours rigor
Algor mortis \_\_\_\_\_\_degrees Not accurate if used solely Body cooling is not uniform Does not follow a linear pattern Fastest during first 2 hours Body habitus may influence rate of cooling
____ cool faster due to body mass/surface area ratio
Higher in girls
____ cools at lower rate
35.6°C - 38.2°C
Infants
Obese
warm and not stiff
less than < 3 HRS.
warm and stiff
BET. 3-8 HRS.
cold and stiff
BET. 8-36 HRS.
cold and not stiff
> 36 HRS.
Determined by degree and rapidity of decomposition
Accelerated decomposition raises ____ level
Time is only one factor so unreliable solely
Vitreous Potassium
potassium
STOMACH CONTENTS
Gastric emptying varies from person to person, amount of meal and time of the day
Half gastric emptying time: ___ hrs
Stress will delay digestion
4 hours
Size of the last meal The stomach usually starts to empty within 10 minutes after the first mouthful has entered. light meal - \_\_\_\_hrs medium sized meal - \_\_\_\_\_ heavy meal \_\_\_\_\_
1 1/2 to 2 hrs
3 to 4 hrs
4 to 6 hrs
Insect activity- from egg stage to adult stage.
ENVIRONMENTAL FACTORS
Autolysis: - aseptic breakdown
- pancreas
Putrefaction: breakdown due to bacteria
- 1st sign is greenish color of LQ abdomen
- greenish-black color of face/neck
- swelling
- protruded eyes and tongue
- purge fluid
Gas formation- slippage of skin with blister and marbling ( rxn of hgb and hydrogen sulfide). Skin from green to black.
Hair will slip from the scalp
brain: liquefied
Decomposition: after 24hrs in hot weather while slower process in a wk or 2 in temperate climates
Skeletonization: a week to years
Adipocere: fats will undergo fatty acid transformation
DECOMPOSITION
Rigor mortis present all over. Hypostasis well-developed and fixed. Greenish discoloration showing over the caecum.
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES OCCURING IN TROPICAL REGIONS
12 hours
Rigor mortis absent all over. Green discoloration over whole abdomen and spreading to the chest. Abdomen distended with gases.
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES OCCURING IN TROPICAL REGIONS
24 hours
Ova of flies seen. Trunk bloated. Face discolored and swollen. Blisters present. Moving maggots seen.
ok
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES OCCURING IN TROPICAL REGIONS
48 hours
Whole body grossly swollen and disfigured. Hair and nails loose. Tissues soft and discolored.
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES OCCURING IN TROPICAL REGIONS
72 hours
Identification of bodies
a. non-scientific methods
b. Scientific methods
Identification of bodies
- by relatives, friends
- by documents, clothing, scar tattoo
- jewelries
- by exclusion
non-scientific methods
Identification of bodies
- fingerprints
- dental identification
- DNA testing
- ante and postmortem x-rays
scientific methods
filing / prosecution of case filing of death certificate Insurance claim Repatriation Peace of mind among relatives
Importance of ID
Soft viscera putrefied
1 week
Only more resistant viscera distinguishable
Soft tissues largely gone
2 weeks
Bone skeletonized
one week
Very little change is water is cold. Rigor mortis may persist
The skin on the hands and feet became sodden and bleached. The face appears softened and has a faded white color
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES WHEN THE BODY HAS BEEN SUBMERGED IN WATER
4-5 days
Face swollen and red. Greenish discoloration on the eyelids, lips, neck and sternum.
Skin of the hands and feet wrinkled. Upper surface of brain greenish in color
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES WHEN THE BODY HAS BEEN SUBMERGED IN WATER
5-7 days
Skin wrinkled. Scrotum and penis distended with gas. Nails and hair still intact. Lungs, emphysematous and covered the heart.
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES WHEN THE BODY HAS BEEN SUBMERGED IN WATER
1-2 weeks
Abdomen distended, skin of hands and feet come off with nails like glove
CHRONOLOGICAL SEQUENCE OF PUTREFACTIVE CHANGES WHEN THE BODY HAS BEEN SUBMERGED IN WATER
4 weeks; 6-8 weeks
Importance of ID filing / prosecution of case filing of death certificate Insurance claim Repatriation Peace of mind among relatives
ID of Remains
Humans have 20 deciduous (baby) teeth
4 maxillary incisors , 4 mandibular incisors
2 maxillary cuspids, 2 mandibular cuspids
4 maxillary molars, 4 mandibular molars
EXAMPLE: (dental eruption)
Mandibular incisor: usually at 6-7 months
3rd molar: 17-24 years old
Humans usually develop 32 permanent
teeth
-4 maxillary, 4 mandibular incisors
-2 maxillary cuspids, 2 mandibular cuspids
-4 maxillary premolar, 4 mandibular premolar
- 6 maxillary molars, 6 mandibular molars
Dental
Comparison of physical attributes
Distinctive marks- tattoo, scar, jewelry
Visual ID
Circumstancial evidence- dentures, wallet, clothes, eyeglass
NON-SCIENTIFIC METHODS OF ID
Scientific Fingerprint : remove the skin Dental x-ray Total body radiographs- bullet DNA: muscle, marrow, molar-dental pulp Non-Scientific 1. Hydrogen peroxide (Agua oxinada) - to clean the skin to see tattoo 2. Carefully observing the jewelries 3. UV or infrared light may show tattoo
Decomposed, Charred, Non-skeletonized Human Remains
- 1st determine if it is human!
- Then get DNA- bone with marrow
- Collect the clothing, jewelry, personal
effects - Forensic anthropologist – may determine the sex, race, age, height.
Skeletal Remains
Causes of sudden natural death in adults
“ sudden, unexpected death due to natural disease is relatively uncommon between ages of 1 and 30.”
Sudden death: died within __ HRS
NATURAL DISEASE
24
Instant
- W/in seconds Non-instant
- W/in minutes
Sudden Deaths
A. Coronary Artery Disease - 75% of all sudden deaths
- mechanism of death: fatal cardiac arrhythmia. 80% from ventricular Arryh.
20% from asystole
- most common autopsy findings: coronary artery atherosclerosis.
- for death to occur 75% of coronaries must be blocked
CAD
- 2nd most frequent findings: ischemic fibrosis
Infarcts <24Hrs, “wavy fibers.”
Arrhythmia, no gross findings.
Cause of Death: Arteriosclerotic Cardiovascular Disease (ASCVD)
B. Hypertensive Cardiovascular Disease
- heart >350 gm
- associated with renal findings and coronary atherosclerosis.
C. Cardiomyopathies
- congestive (CHF) dilated cardiomyopathy
-asso. with chronic alcohol abuse
-peri / post partum cardiomyopathy
-Hypertrophic Cardiomyopathy: enlarged but not dilated. Thickened septum
-50% is autosomal dominant
-history of dropping dead during exercise
-Restrictive Cardiomyopathy-least common
-amyloidosis
-sarcoidosis
-glycogen storage disease
-hemochromatosis
I. Causes of sudden natural death in adults
Coronary artery spasm-prinzmetal angina
Coronary artery dissection
Congenital anomaly
D. Other coronary artery abnormalities w/c may cause sudden death
Floppy mitral valve- myxoid degeneration
Calcific aortic stenosis-RHF
endocarditis
E. Valvular disease that may cause sudden death
Infectious- multiple sections of the heart for histopath
Hypersensitivity
Giant cell myocarditis
F. Myocarditis
Acute aortic dissection- asso. with atherosclerosis and hypertension
Syphilytic aortic aneurysm
G. Abnormalities of aorta
Causes of sudden natural death in adults
A. Coronary Artery Disease
B. Hypertensive Cardiovascular Disease
C. Cardiomyopathies
D. Other coronary artery abnormalities w/c may cause sudden death
E. Valvular disease that may cause sudden death
F. Myocarditis
G. Abnormalities of aorta
II. Central Nervous System Disorder
A. Epilepsy B. Subarachnoid Hemorrhage C. Intracerebral Hemorrhage (stroke) D. Cerebral Infarct (stroke) E. Meningitis F. Hydrocephalus G. Psychiatric D/O: schizophrenia
III. Respiratory
a. Pulmonary thromboembolism
b. Amniotic fluid embolism
c. Asthma
d. Pneumonia
e. Acute epiglottitis: edema of epiglottis
f. Massive hemoptysis
g. Spontaneous pnemothorax
IV. Gastrointestinal – sudden death
a. Massive hematemesis
b. massive stomach bleeding
c. Strangulated hernia
d. Diabetes mellitus
e. Pancreatitis
V. Liver Diseases-sudden death
a. Liver: Massive fatty change
b. non-traumatic abdominal hemorrhage
VII. Spleen
Rupture
Absence of spleen
VIII. Miscellaneous sudden causes of death
Rupture tubal pregnancy
Undiagnosed cancer
Sudden Death in Children
Sudden infant death syndrome (SIDS)
Sudden Infant Death Syndrome
Maternal risk factors:
Scene investigation:
A break or solution in the continuity of the skin or tissues of the body.
Wound
Types:
Wound
Close wound
Open wound
injury produced by blunt object striking the body or impact of the body against a blunt surface.
Blunt Force Injury
Blunt Force Injury
Severity due to several factors
Nature of weapon Amount of body surface Amount of force Time Region
wound where there is no break in the overlying skin or tissue.
Close Wound
Close Wound
typs
a. Superficial close wound
b. Deep close wound
a. Superficial close wound
- Petechiae
- Contusion
- Hematoma
b. Deep close wound
- Sprain
- Fracture
- Dislocation
- Concussion
- Internal Hemorrhage
minute, pin-point, circumscribed extravasation of blood in the subcutaneous tissues or underneath the mucuos membrane.
- Petechiae –
– discolorations of the skin caused by bleeding into the tissues from ruptured blood vessels.
2. Contusion (Bruise) Color is not always reliable Red, violaceous, purple, dark blue Hemoglobin: broken down to color green, dark yellow, pale yellow Resolve from days to weeks
large extravasation of blood in a newly formed cavity secondary to trauma characterized by swelling, discoloration of tissues, and extravasation of blood underneath the tissues.
- Hematoma
straining or tearing of the articular tendons, ligaments and muscles characterized by swelling, discoloration of tissues involved and extreme pain.
- Sprain
it is a break solution in the continuity of the bone tissue resulting from violence or from some existing pathology.
- Fracture –
displacement of the articular surfaces of the bones forming the joints usually secondary to trauma.
- Dislocation
resulting from a sudden jarring or stunning of the brain which follows a head injury.
- Concussion
bleeding usually in the cavity or organs inside the body.
- Internal Hemorrhage
– wound where there is break in the overlying skin or tissue.
Open Wound
open wounds
- Abrasion
- Incised wound
- Lacerated wound
- Punctured wound
- Stab wound
- wound produced by explosion of explosive material
- Avulsion
- Gushot & Shotgun wound
An injury to skin in which there is removal of the epidermis by friction against a rough surface or destruction of the superficial layers by compression.
- Abrasion
reddish brown appearance
Heal without scarring
Antemortem abrasion
Yellow, translucent, parchment like appearance
Postmortem abrasion –
Types of abrasions
- scrape abrasions
- Brush burn abrasion
- Impact (pressure) abrasions
- Patterned abrasion
scraping type of injury. Ex. Dragging abrasion, scratches
- scrape abrasions-
commonly use in large area of the body
- Brush burn abrasion-
skin crushed by force.
- Impact (pressure) abrasions
pattern of object imprinted on the skin.
- Patterned abrasion
Stages of Healing
1st stage: Scab Formation. within 24 Hrs
2nd stage: Epithelial Regeneration. visible in 3rd day post injury
3rd stage: Sub epidermal Granulation. 5-8 days
4th stage: Regression. Dec. vascularity 12 days post injury
produced by forcible contact with a sharp-edged instrument characterized by gaping smooth edges of the wound; sharp extremities; shelving and profuse bleeding of the wound.
- Incised wound
produced by blunt instrument and is characterized by irregular edges of the wound.
- Lacerated wound
produced by sharp-pointed instrument and is characterized by small opening of the wound.
- Punctured wound
produced by sharp-edged and sharp-pointed instrument.
- Stab wound
A form of laceration ripping the skin and soft tissue off the underlying fascia or bone.
- Avulsion
May have severe internal injuries sans external evidence.
Rib / sternal fractures: maybe due to CPR
Cardiac rupture due to steering wheel
Blunt Force Injury to the Chest
Liver most frequently injured
Spleen: minimal force may cause rupture in typhoid, malaria, IM, hemophilia, leukemia
Kidney: most common is contusion
Blunt Force to the Abdomen
“Bumper fracture”
-must measure the location from the heel
Complication of fractures:
-fat embolization: seen in histopath sections of the lungs
Defense and Offensive wounds
Extremities Injury due to Blunt Force Trauma
Epidural Hematoma
Subdural Hematoma
Subarachnoid H’ge
Intracerebral H’ge
Head Injuries Caused by Blunt Force
Scalp : will show the extent of injury
Blunt force injury to the head
Alteration in the normal alignment of the cervical vertebral column Hyperflexion (chin to chest) Hyperextension (head backwards) Compressive (head landing) Torsion Elongation (Hanging) Axis or C2, most commonly injured
Blunt Force to the Neck
Sharp Wounds
Stab wounds
Incised wounds
Chop wounds
Produced by pointed instrument like knife or ice pick
Skin markings may tell the type of weapon used
Homicidal, suicidal or accidental
Defensive stab wounds
Stab wounds
It is common for stab wounds to be altered by surgeons.
MELO must determine if px was brought to hospital
Don’t remove the knife from the body unless fingerprint was taken.
Examine the clothes
Post-mortem SW- yellow to tan in color
Stab wounds
Wound produced by sharp weapon. Wound is longer than the depth.
Lacking bridging tissue
Usually not fatal
Defensive incised wound
Incised wounds
Caused by heavy instrument or weapon
Ex. Axes, machete, meat cleaver
Incised wound with bone cut/groove
Soft tissue h’ge means px is still alive when injury was inflicted
Chop wounds
Whenever a gun is fired, the exiting bullet is accompanied by:
A jet of flame, 1-2 inches in length
(3 inches Pistol, 6 inches Rifle)- Solis
A cloud of gas
Unburnt gunpowder
Carbon or soot from burnt gunpowder
Vaporized metal from the bullet
Gun Shot Wounds
- Usually smaller than the missile owing to the elasticity of tissue.
- Edges are inverted.
- Usually oval or round depending upon the angle of approach of the bullet.
- Contusion collar or contact ring/ abrasion ring is present due to invagination of the skin and spinning of the missile.
- Tattooing or smudging may be present when firing is near
- Always present after fire.
- GSR/ Paraffin test may be positive.
- Bright to redness due to COHg is present.
- Bursting effect is present
Entrance Wound
Gunshot Wound
- Usually bigger than the missile.
- Edges are everted.
- It does not manifest any definite shape.
- Contusion collar is usually absent.
- Absent.
- Maybe absent if missile is lodge in the body.
- GSR/ Paraffin test is always absent.
- Absent
- Absent
Exit Wound
Gunshot Wound
Categories of Gunshot Wounds
Contact
Near contact
Intermediate
Distant
A. _________1
The muzzle of the gun is pressed against the skin
All the materials exiting the muzzle goes beneath the skin
_______2 - detailed imprint of the heated muzzle to the skin
_______3 – tears that radiate from the edge of the wound caused by the blast effect that follows the sudden release of gases between the skin and underlying bone (skull)
Contact Wounds
- Hard-contact would
- Ironing effect
- Stellate wound
B. ___________1
Ironing effect
Soot and small amount of gunpowder is deposited on the wound edges
If the gap between the skin and muzzle is angled, products escape in one direction – _____2 pattern
- Loose Contact
2. teardrop
2-3 inches to 6-7inches
Scorching of the skin, but no ironing effect
large amount of soot/ smudge is deposited
Little amount of gunpowder may be scattered on the surface
Near Contact
6-7 inches to 12- 18 inches (Spitz)
The principal indicator of close range fire is stippling or powder tattooing.
Tattooing or Stippling is caused by unburned particles of gunpowder striking the skin resulting in punctuate abrasions in the skin surrounding the entrance wound
May be distributed circumferentially or more densely scattered on one side.
Powder tattooing cannot be wiped away
Intermediate Range/ Close-Range
> 12-18 inches (Spitz)
> 2 feet (24 inches), >36 inches (long firearm)
Round to oval with sharp punched out margin
Absence of ironing, smudging or tattooing
Abrasion ring – scraping the raw edges of the skin
Irregular abrasion ring – impact at an angle
Distant Gunshot
One cannot determine the caliber of bullet by examining the GSW.
However 9mm, usually produces 9mm holes
Suicide: most use hand gun, most are contact, most are on the head, single shot.
Temple, mouth, under the chin, between the eyes
25% w/ suicide note; gun still on hand
GSW
\_\_\_\_\_: inadequate oxygenation of tissue Asphyxial Deaths: Suffocation Strangulation Chemical asphyxia
Asphyxia
Failure of oxygen to reach the blood A. environmental suffocation: “no air” -negative autopsy B. smothering: obstruction of nose and mouth accidental, homicidal, suicidal -may show bruising on the mouth
Suffocation
Blockage of internal airways Most are accidental Aspiration of food among stroke victims 25% agonal aspiration Children: toys
Choking
Pressure on the chest and abdomen
Accidental
Ex. Parent rolled over the baby during sleep
Autopsy: congested face, neck, scleral h’ge
Mechanical asphyxia
Occlusion of blood vessels in the neck 2nd to external pressure
TYPES
-hanging
-ligature
-manual
Mechanism of Death: pressure on the neck artery »_space;> no oxygen to the brain
Blood to the brain, 2/3 supplied by carotid artery
11 lbs necessary to occlude the carotid
15 sec of occlusion»> loss of consciousness
STRANGULATION
Weight of the head is 10-12 lbs Complete suspension is not necessary All hanging are suicide Inverted “V” at the side of the neck Above the larynx Furrow is yellow then brown on drying 1/4 of cases with conjunctival h’ge 10% with fractured hyoid Marking on the neck may suggest the type of cord used Linen, no marking
Hanging
Most are homicide Victim: Woman in relation to rape Ligature mark is horizontal Below the larynx Face congested with scleral, conjunctival h’ge
Ligature Strangulation
Always homicide
Death is not due to vaso-vagal stimulation
Death is due to occlusion of blood vessels
Victims: Woman
Marks on the neck
H’ge on the soft tissue of the neck
Hyoid fracture is valid when surrounded by h’ge
Manual Strangulation
Carbon monoxide
Hydrogen cyanide
Hydrogen sulfide
Chemical Asphyxiant
- killing of newborn
- born alive or dead?
- hydrostatic test
Neo-naticide
No external head trauma
Positive h’ge in the brain
Due to violent shaking
of the head
Shaken Baby Syndrome