Forensic Issues/Physical Injury Flashcards
1
Q
How does the (proximate) cause of death differ from the mechanism (immediate) cause of death?
A
- The proximate = the “real” cause of death
- How did they die?/What killed them = Cause of death
- Why did someone die suddenly? = Mechanism of death
- Mechanism of death = Final pathological cause of death
2
Q
Accurate Death Certificate Schema
A
- (Immediate) Cause of Death (Mechanism) DUE TO (proximate) Cause of Death
- Need to have the cause of death on the certificate
- Ex. Massive hemorrhage due to gun shot wounds
3
Q
The Manner of Death is a opinion. What elements may such an opinion encompass besides an autopsy?
A
- The medical examiner has no duty to families. They work for society not families
- You are most likely to be killed by someone in your family or someone you know
4
Q
List the manners of death
A
- Natural (death is not due to foul play)
- Accident
- Suicide
- Homicide
- Undetermined
5
Q
Is it ever legitimate to formally list a manner of death as “undetermined”?
A
YES
- Ex. Cardiorespiratory breast is not legitimate cause of death
6
Q
Why are homicide and murder not synonymous?
A
- Homicide is putting someone to death
- Murder (can be premeditated)
- Murder is more a legal term whereas homicide is death certificate terms
- Murder can be classified as homicide. Homicide includes all unnatural death caused by humans
7
Q
Why are there few hospital autopsies?
A
- If you misdiagnose, it is a law suit
- Pathologists don’t like to do hospital autopsies because it takes a long time, requires a lot of money, and can get sued. Everyone can get sued
- Insurance companies don’t want to pay for it. So it is not a good thing
- Medical examiners can’t be sued in their office because they have sovereign immunity
8
Q
If a case appears ‘obvious’, why do a forensic autopsy?
What role does ‘the family’ play in decision-making, in terms of when and if a (ME) autopsy is performed?
A
- Even if the case seems obvious, families might want an autopsy because they are so sure that they know what happened even if it differs from what you think and so the only way you can refute them is by getting a forensic autopsy
- But sometimes families insist they don’t want an autopsy but you have no duty to the family so use your best judgement
9
Q
Who can legitimately certify death in the US?
A
- Medical examiner **
- Any licensed physician
- Coroner
- Justice of the Peace
10
Q
Major forms of Body Cooling and Changes
A
- Algor Mortis
- Livor Mortis
11
Q
What is Algor Mortis?
A
cooling of the body after death and can cool in a uniform rate but depends upon the ambient temperature outside
12
Q
What is Livor Mortis
A
After you die, and there is not systemic circulation, red blood cells go to dependent portion of bodies and become fixed. So when you press on body, it is fixed and you know roughly what time it occurs over. Also depends on temp.
13
Q
List and describe the forms of decomposition
A
- Putrefactive - died in a setting which is temperate and humid (like Florida). Large volumes of fluid accumulate. Skin begins to slip and has color changes (grey, blue, greenish). Decomposition begins over the cecum (where biggest load of bacteria is. Those organisms invade after death. Green patch)
- Adipcere Formation- body found in water. Lipid layer encasing the body esp in fresh water and less so in salt water
- Mummification - kind of rare in US. Bodies that die in arid places like deserts can dry out and mummify.
14
Q
Wrong Media Perceptions
A
- Time of death - hard to specifically say a time of death
- Rapidity of testing - Mass spectroscopy and other testing take a fair amount of time including toxicology testing (for common drugs of abuse)
- Data bases - facial recognition things on TV where you can identify people is not likely
- Justices of the Peace, Coroners, Medical Examiners, Crime Scene Investigators/Police (these ‘terms’ are not generally synonymous/interchangeable).
15
Q
What is the role of the medical examiner?
A
- To assign a cause of death (COD)
- To render an opinion as to the manner of death
- Duty is to SOCIETY
16
Q
The focus of a forensic examination/inquiry is not ? death (other than to rule out/observe discernible signs) or consider circumstances in terms of the probabilty of foul play/unnatural death, or contributions thereof
A
Natural
17
Q
What systems are extremely susceptible to radiation injury?
A
Hematopoietic and lymphoid systems
18
Q
True capability of forensic specialists to accurately ascertain a time of death
A
- If body temp is warm and body is not stiff = dead not more than 3 hours
- If body temp is warm and body is stiff = dead 3 to 8 hours
- Body temp is cold and body is stiff = dead 8 to 36 hours
- Body temp is cold and body is not stiff = dead more than 36 hours
19
Q
Difference between Medical Examiner and Coroner
A
- Coroners are usually elected and are not required to be physicians. If an autopsy is needed, a coroner will frequently consult with a pathologist or forensic pathologist.
- Medical examiners, in most cases, are appointed and must be physicians.
20
Q
Forensic Specialists
A
1. Criminology –Profiling –Fingerprints –Voiceprints –Facial recognition –Handwriting –Other
- Odontologist - dentists
- Anthropologist - involves applying skeletal analysis and techniques in archaeology to solving criminal cases.
- Entomologist - specialist of bugs in decomposition. (Especially lay maggots in eyes. Maggots want to get into the interior of bodies and can do it via gun shot wound).
- Laboratory
- Toxicology
- Histomorphology
- Ballistics
- Hair and fiber
- Patterning studies, i.e. tool/tire marks
- Gunshot residues
- DNA/nuclear, mitochondrial
- Other, clinical laboratory analyses
21
Q
Difference between law enforcement vs medical examiners
A
- Law enforcement role can include Ballistics (like knowing which weapon caused the murder). They use blood and body fluids for DNA evidence. They can also be at the scene of the crime
- Medical examiners- licensed physicians that perform autopsies to figure out the cause of death
22
Q
Role of hospital autopsy
A
Performed in order to provide scientists with greater information about pathology and also to keep a check on hospital care and ensure doctors are providing the best services they possibly can.
23
Q
Full Autopsy Technical Approach
A
???? An autopsy takes the form of six stages: - Y-Incision. - Removal of Organs. - Stomach Contents. - Sample Collection. - Head and Brain examination. - Conclusion.
24
Q
10 leading causes of death by Age
A
- Homicide rate is highest - 15-34 (homicide done by women is 1.5% so men are most dangerous)
- Overall gun violence death is going down
25
What kind of death is SIDS?
Natural death
26
What kind of death is low bar pneumonia?
Natural death
27
What are blunt force injuries?
- Abrasion
- Contusion
- Laceration
28
What is a laceration?
Always due to blunt force (not due to sharp object). Skin splits. Have soft tissue bridges.
29
What is a contusion?
- Colors?
Bruise
- Yellow = Bruise is at least 18 hours old
- Blue, purple, red = do NOT assist in dating bruises
- Brown = mix of colors and therefore not useful
30
What is abrasion?
• Abrasion - may ooze. Superficial
- Gliding - usually seen in motorcycle deaths.
- Injuries on bony prominence
- Can see patterned abrasions (like dots everywhere)
31
Incise wounds = ?
Stabbing wounds (not called lacerations)
32
What is the salient wounding formula for guns/projectiles?
- KE = 1/2m x V2
- Kinetic energy formula
- Velocity is most important element **
- VELOCITY more important than Mass
33
three main types of abrasions:
1. Brush (or scrape or gliding) abrasion
2. Impact abrasion
3. Patterned abrasion: Occurs when the
abrasion recapitulates the surface appearance of the instrument
- Dicing injuries in vehicle accidents
34
What id s brush or (scrape/gliding) abrasion?
Brush (or scrape/gliding) abrasion: produced by grazing or sliding motions. i.e. the applied force is tangential to the body surface. Close inspection reveals “rolls” or “heaps” of tissue at the margin of the wound opposite the direction of force. Large confluent scrapes are known as “brush burn” (or gliding abrasions)
35
- A wound in which
(primarily) the epidermis is injured. It is produced by friction scraping away epidermis or crushing of the epidermis by direct
pressure or a blow tangential to the surface
- oozes serum or blood (but does not tend to bleed profusely) and generally heals by formation of a scab
Abrasion
36
The extent and severity of a contusion depends on?
a. Amount of force applied
b. Vascularity of tissue injured
c. Type of tissue injured: areolar (loose or
thin) tissue such as the eyelids - tends to bleed more
d. Location of the tissue: tissue overlying
hard bony structures is more easily bruised
e. Easy bruisability: advanced age, cirrhosis
of the liver, coagulopathies, etc.
37
Wounding formula
W = E x 1/T x 1/A x K
- W = wound
- K = modifying factors (elasticity of the striking object or the tissue being injured etc)
- E = Energy transferred = ½ MV2
- T = Period of energy transfer (time)
- A = Area of application of force
- Inverse relationship to time and area. Small objects with less surface cause damage than bigger object. More quickly you hit someone, worse injury than slow.
38
a sharp force injury
in which the depth of the wound track is
greater than the length of the wound on the
skin (deeper than longer). It is produced
when an instrument with a pointed edge is
thrust into the body or the body falls on the
pointed edge”.
Stab wound
39
What is a stabbing instrument?
- Any sharp instrument capable of overcoming the tensile strength of the skin may be used to cause a stab wound.
- Although knives are the most commonly used weapon in sharp force injury, other implements such as scissors, screwdrivers, barbeque forks and kitchen
forks are used.
- (A stab wound by an “ice pick” may appear as a small
caliber firearm or shotgun pellet wound)
40
What are 3 types of guns?
•Long guns
– Bolt/lever action
–Semiautomatic
– (Fully) automatic
•Smooth bores (aka shot guns)
•Hand guns
– Revolvers
– semiautomatics
41
Comorbid factors that might complicate wound healing?
Not only bullets come out of guns
- Dirt, powder, smoke and fire come out as well
- Virtual mini explosion as bullet comes out
42
How does wound patterning contribute to forensic evals?
Examples:
- Double edge blades = more military. Give more of an oval. Incise wounds.
- Cuts on wrists = suicide attempts
- You can see a more curved appearance of the wound if they were stabbed in the same area more than once or they twisted the knife
- Superficial wound but also deep wounds = Hesitation marks. Killer didn't know how much pressure it took to hurt someone
- If someone goes for the face, it is more likely that the killer was someone that they knew
43
Entry Wounds: Ranges
•Contact range: marginal abrasion; soot/powder in depths of wound
- See circle that is around the wound
•Intermediate range: marginal abrasion, powder
tattooing/stippling around wound
- Powder stippling (like little dots all around). Release gun powder that tattoos the face
•Distant range: marginal abrasion, no powder
tattooing/stippling, no soot/powder in the depths of a wound
44
Gun shot wounds of the head
- The adult skull has an inner and outer table separated by the diploe.
- In entry wounds the outer table of the skull is typically sharply circumscribed, and the inner table beveled
- In exit GSWs of the skull – it is exactly the opposite
- Also in the skull, fractures emanating from blunt force or, in some cases gunshot wounds, do not ramify across previous fracture lines (i.e. they ‘stop’ rather than ‘cross’ them). Thus, in certain cases you can ascribe a number to wounds and determine their timing with some accuracy.
- This is generally unlike other areas of the body in which it can be quite difficult to assess the timing of wounds (although it can be done to some extent, depending on the case, utilizing scene/investigative information, or vital physiologic reactions, etc.)
45
What can we say about handguns (low velocity) vs. long guns (high velocity)?
KE = 1/2m x V2
So, in general….
* Low velocity = small entry, no exit (or small exit)
* High velocity = relatively small entry, big exit
- Long guns have more wounding capabilities than hand guns
- Long guns have more energy directed and the bullet is accelerated. There is more velocity involved.
46
Entry and Exit Wounds vs Inner and Outer Table
- External table = compact bone
- Diploe = trabecular or spongy bone
- Internal table = compact bone
- The adult skull has an inner and outer table separated by the diploe.
- In entry wounds the outer table of the skull is typically sharply circumscribed, and the inner table beveled
- In exit GSWs of the skull – it is exactly the opposite
• Entry: As bullet moves through skull, it blows out the inner table (is beveled). Sharp interscription of external.
If exits: sharp interscription of internal and beveling of external
47
1993 Waco Debacle:
| Organization?
Organization = grid it
| - If you find multiple bodies, you explode alpha numeric grid and record them in that square
48
1993 Waco Debacle:
Control of Crime Scene
• Put tags for body remains
• Photo of 35 bodies under that guy
- Lots of bodies buried in bullets
• David Karesh - having sex with wives of the cult members and kids (gave them a star of David)
• A human body in fires
- Typically, you cremate bodies at 2200 F for an hour
- In the compound, there were a lot of flammables and temp was 2500
- At a certain temp, the lipids in brain burst into flame and skull explodes
49
Media reports on gun violence
- Media makes it seem like there is a rise in gun violence but in reality there is actually a decrease in gun violence
50
1993 Waco Debacle:
```
•Macro level: the scene
–Safeguarding (live people first-then the
scene)
–Surveying
–Documenting
–Proper approach to specimen retrieval
```
•Micro level
–Biologic materials retrieval and transmittal vs.
inorganic specimens/substances
51
1993 Waco Debacle:
Principles
```
Scene/the living
• Control
• Survey
• Organization
• Documentation
• Evidence acquisition/securing
```
Medical Examiner
• Bodies
• Recording
• Final
52
Burns:
The clinical significance of a burn injury depends on?
- Depth of the burns
- Percentage of body surface involved
- Internal injuries caused by inhalation of hot and toxic fumes
- Promptness and efficacy of therapy
53
Burns:
- Superficial ?
- Partial thickness?
- Full-thickness?
- Superficial (1st degree) = confined to the epidermis
- Partial thickness (2nd degree) = injury to the dermis
- Full thickness (3rd degree) = extend to the subcutaneous injury
54
Burns:
- What are the greatest threats to life in burn patients?
Shock, sepsis, and respiratory insufficiency
55
Burns:
An important pathophysiological effect of burns is the development of a ? state associated with excess heat loss and increased need for nutritional support
Hypermetabolic state
56
Burns:
Virtually all burns become colonized with ?
Bacteria
57
Burns:
Injury to the ? may develop within 24 to 48 hours after the burn
airways and lungs
58
Hyperthermia:
Result from loss of electrolytes via sweating ?
- Cramping of voluntary muscles is a hallmark
Heat cramps
59
Hyperthermia:
Most common hyperthermic syndrome.
- Onset is sudden with prostration and collapse
- Results from failure of the cardiovascular system to compensate for hypovolemia caused by dehydration
Heat exhaustion
60
Hyperthermia:
Associated with high ambient temp, high humidity, and exertion
- Older adults, individuals under intense physical stress (athletes), and persons with cardiovascular disease are at high risk
- Hyperkalcemia, tachycardia, arryhythmias
- Sustained contractions of skeletal muscle
Heat stroke
61
Prolonged exposure to low ambient temp (esp seen in homeless people)
Hypothermia
62
Hypothermia:
1. Direct effects
2. Indirect effects
1. Direct effects
- mediated by physical disruption within cells by high salt concentrations caused by the crystallization of intra and extracellular water
2. Indirect effects
- Result from circulatory changes which vary depending on the rate and duration of temp drop
- Slow chilling may induce vasoconstriction and increase vascular permeability, leading to edema and hypoxia
63
Ionizing Radiation (Key Concepts p 432)
- Ionizing radiation may injure cells directly or indirectly by generating free radicals from water or molecular oxygen
- ionizing radiation damages DNA; therefore, rapidly dividing cells such as germ cells and those in the bone marrow and GI tract are very sensitive to radiation injury
- DNA damage that is not adequately repaired may result in mutations that predispose affected cells to neoplastic transformation
- Ionizing radiation may cause vascular damage and sclerosis, resulting in ischemic necrosis of parenchymal cells and their replacement by fibrous tissue
64
Electrical Injuries
- What is high and low voltage
- low voltage = in the home and workplace
| - high volt = currents carried by high power lines or produced by lightening
65
Electrical Injuries:
2 types of injuries?
1. Burns
2. Ventricular fibrillation or cardiac and respiratory center failure, resulting from disruption of normal electrical impulses
- Type of injury and the severity and extent of burns depend on the strength, duration, and path of the electric current in the body
66
Particular form of gas embolism that occurs when individuals experience sudden decreases in atmospheric pressure
Decompression Sickness
- Ex. Scub and deep sea diving
