SECTION 6: FORENSIC MEDICINE ================================================ Written by: Dr. Rana Faizan Ali M.B.B.S (Dali University, Yunnan, P.R China) PM&DC (I,II,III) Javairia Zulfiqar M.B.B.S (Dali University, Yunnan, P.R China) Interne Revised by: Dr. Muhammad Shoaib M.D (Kyrgyz-Russian Slavic University, Bishkek, Kyrgyzstan) PM&DC (I,II,III) ===================================== Forensic Medicine Curriculum given by PMDC for Step 1: 1. Medical Law 2.Traumatology
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Forensic Medicine SEQs asked in Last 4 PMDC Papers:
Q1: Define Bruises? What is chemical Antidote?
Q2: What is the function of PMDC? What are the privileges of registered Medical
Practitioner?
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Q1: Bomb explosion cause what kind of injury to one's body?
Q2: What kind of duties of doctor while handling poisoning case?
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Q1: What information can be inferred from the Fire Arm Injury [5]
Q2: Medical Negligence:
a. Define Medical Negligence? [1]
b. Mention the Types of Medical Negligence? [2.5]
c. Difference between the Civil and Criminal Negligence? [1.5]
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Q1: What is Stab wound?
Q2: What is Professional Misconduct?
MEDICAL LAWS
Adult: A person who has reached age of 18 years (for males) or 16 years (for
females) or who has attained puberty, whichever is earlier.
Authorized Medical Officer: A medical officer or Medical board constituted by
provincial government is called authorized medical officer or board.
Qisas: means punishment by causing similar hurt at the same part of the body of
convict as he has caused to victim.
Diyat: means compensation specified in section 323 payable to heirs of victim by
the offender.
Arsh: means compensation specified in Qisas and Diyat Ordinance paid by the
offender to the victim or his heirs.
Daman: means compensation determined by the court to be paid by the offender
to victim for causing hurt liable to Arsh.
Wali: is legal heir of victim or deceased or victim himself, in case of qatl; wali is
heir of victim or if the victim is unknown then government.
Medical Practitioner: it is the one who possesses a recognized medical
qualification, as defined in Medical council Act.
Laws Relating to Death:
Qatl-i-Amad: to cause death of a person with full intention and with the
knowledge of causing death with full intention of a specific person.
Qatl-i-shibh-i-Amad: Intention is to cause harm but death has occurred, death of
same or any other person by means of a weapon or an act which usually is not
likely to cause death.
Example: Person "A" gives blow on abdomen of "B" and "B" goes into shock and
death occurs. In ordinary course of nature blow is not likely to cause death.
Qatl-i-khata: to cause death or harm, this leads to death without intention by
mistake of act.
Example: Hunter shoots a bird but a man is killed.
Qatl-i-Sabab: to cause death of a person or harm, this leads to death without any
intention by an unlawful act.
Example: "A" digs a pit for some purpose and "B" falls into it while passing over it
and is killed.
Laws Relating to Hurt:
Definition: whosoever causes pain, harm, disease, injury to any person or impairs,
disables, dismembers any organ of body or part of body of a person; without
causing death is said to cause hurt.
Types of Hurt:
1. Itlaf-i-Udw: whosoever dismembers, amputee, severs any limb or organ of
body of another person.
2. Itlaf-i-Salahiyat-i-Udw: whosoever destroys or permanently impairs the
functioning power of an organ of body of another person or causes permanent
disfigurement.
3. Shajjah: causes hurt/injury on head or face of any person which does not
amount to itlaf-i-udw and itlaf-i-salahyiat-i-udw.
Types of shajjah:
a) Shajjah-i-Khafifah: bone is not exposed by injury.
b) Shajjah-i-Mudiah: bone is exposed without fracture.
c) Shajjah-i-Hashimah: bone is exposed and also fractured but its end is not
displaced.
d) Shajjah-i-munaqqilah: underlying bone is exposed, it is fractured and its end is
displaced.
e) shajjah-i-ammah: underlying bone is fractured and membranes are exposed
but no damage to brain.
f) shajjah-i-damighah: there is fracture of bone of skull, membranes are exposed
and damage to brain.
4. Jurh: whosoever causes hurt on any part of a person other than head and face,
which leaves mark of wound either temporary or permanent.
Allopathic System Ordinance 1962:
Prevention of Misuse:
1. Prohibition of use of word doctor and its abbreviation unless he/she is an RMP
or a person whom a doctor's degree other than a medical degree has been
confirmed.
2. Prohibition of use of medical degree or diploma unless issued by institution
recognized by PMDC.
3. Prohibition of surgical operations by an unqualified person (circumcisions and
injections and abscess drainage can be done)
4. Prohibition of prescription of some drugs (antibiotics) unnecessarily.
5. Restriction on the sale of medicines unless labeled and formula is written on
packing or within packing.
Functions OF PMDC:
1. Supervision of standards of proficiency for registration:
a. Recognition of basic register able medical and dental qualification in and
outside Pakistan.
b. Recognition of additional postgraduate qualification granted in and out of
Pakistan.
c. Power of having detailed information of courses of study and methods of
examination of all those institutes whose qualification is recognized.
d. Power of appointing inspectors to check the standards of teaching and
examination.
2. Maintenance of official register of medical and dental practitioners:
There are 3 parts of PMDC register:
Part 1: Provisional registration for one year. it continues till the members goes on
paying fee.
Part 2: Registration after completing MBBS.
Part 3: Registration for higher Post graduates degree this is open for public for
their interest.
3. To take disciplinary measures
There are 3 punishments:
-Warning
-Temporary removal of name from PMDC registers.
- Permanent removal of name from PMDC registers.
Appeal against PMDC decisions are made only in High Courts.
Privileges of an R.M.P (Registered Medical Practitioner):
Employment: no one other than RMP should be competent to hold dental or
medical appointment in civil or military.
Medical Certificate: no medical certificate should be valid unless signed by RMP
giving his registration number.
Fee for attendance: no person other than RMP should be entitled to charge fee
for professional services.
Dangerous Drug Prescription: only RMP can prescribe drugs of addiction.
Obligations of an RMP:
1. RMP must notify the change of his or her address to PMDC in 30 days.
2. RMP must not use any
-Name
-Title
-Symbol
-Any other qualification that is not in notice of PMDC.
Medical Ethics: It means the normal principles which should guide the
members of Medical profession in course of their practice & their dealing with
their patients and other members of profession.
The Geneva Declaration (1948):
The world medical association at its 3rd general assembly at Geneva in September
1948 adopted certain codes of ethics in the form of Oath to be taken by all
Members of medical profession, at the time of entering into medical profession.
Hippocratic code:
1. I solemnly pledge myself to devote my life to service of humanity
2. I will give my teachers due respect and gratitude.
3. I will serve my profession with devotion and dignity.
4. Health of my patient will be my first priority.
5. I will respect secrets which are confined in me.
6. I will maintain the honor and noble traditions of medical profession.
7. My colleagues will be my brothers except.
8. I will not permit consideration of religion, nationality to intervene between my
duty and my patients.
9. I will maintain utmost respect for human life from time of conception till birth.
10. Even under threat i will not use my medical knowledge contrary to the laws of
humanity.
Duties of a Doctor:
-what a doctor must do?
-what a doctor must not do?
Duties in General: a doctor must have always maintained the highest standards of
professional conduct. Doctor should not practice by motives of profit. Following
practices are unethical:
1. Self advertisement.
2. Connection with non-qualified person.
3. Receiving any money from patient other than fee.
4. Any abuse of his skills etc.
Doctor-Patient Relationship:
1. A doctor must be decent and co-operative with patient.
2. Complete loyalty to patient.
3. Preservation of absolute secrecy.
4. Emergency care as a humanitarian duty.
Doctor-Doctor Relationship:
Basis of Doctor-Doctor relationship is
1. Cooperation
2. Understanding
3. Avoiding of Professional Jealousy.
Professional Secrecy: It is an implied term of contract between the doctor
& his patient. The doctor is obliged to keep secret; all that he comes to know
regarding the patient during treatment.
Following Points May Be Noted:
Should not disclose illness of his patient with or without consent of the patient.
In divorce cases, no information should be given without the consent of client.
In case of reporting medical journals, patients identity should not be disclose.
In case of examining dead body, certain facts found, the disclosure of which may affect the reputation of the decreased or may cause mental suffering to relatives in such cases doctors should maintain secrecy.
Professional/Medical Negligence: Absence of reasonable care and skill,
or willful negligence of a medical practitioner in the treatment of a patient, which causes injury or death of the patient.
1. Civil Negligence: It is a failure to apply reasonable degree of skill and care by
medical practitioner while treating his patient, and responsibility or burden lies on
the Patient. Cases are dealt with civil courts.
Examples are: -Failure to give ALTS in injury cases.
-Failure to give X-rays to doctor in cases of injury to bones or joints in which there
is doubt about diagnosis.
-Excessive exposure of patient to radiation.
-Insufficient care while using dangerous drugs.
2. Criminal Negligence: When a doctor while treating the patient behaves in a
wicked manner showing complete disgrace and disregard for safety of patient's
life resulting into death of patient. He has committed criminal negligence. Such
cases are dealt with criminal courts.
Examples are: -Injecting anesthetic in fatal dose or in wrong tissue.
-Amputation of wrong finger, wrong limb or removal of wrong organ.
-Leaving sponges or instruments in abdomen.
-Giving wrong blood.
-Gangrene after tight plasters.
3. Contributory Negligence: It is defined as concurrent negligence by both patient
and doctor.
4. 3rd Party Negligence: This is done by paramedical staff, nurses, and medical
students, here doctor shares the responsibility, as he is respondent superior.
Cases dealt with civil courts.
Precautions against Negligence:
-Diagnosis where possible confirmed by laboratory tests including biopsy.
-X-rays should be routinely advised in case of injury of bones or joints or where
diagnosis is doubtful.
-Consultation with a specialist should be suggested in obscure cases.
-Immunization should be considered a necessity where there is danger of
infection.
- Sensitivity should be done before injecting preparations likely to cause
anaphylactic shock.
-No experimental procedure should be done without prior consent.
-No procedure should be undertaken beyond one's skills.
Res Ipsa Loquitur: The professional negligence of a doctor must be proved in
court by the expert, evidence of another doctor.
Examples:
1. Fail to give anti-titanic serum in case of injury causing tetanus. 2. Burn by x ray therapy. 3. Prescribing over dose of medicine causing ill effect.
4. Failure to remove swab from abdominal cavity during operation which may leads to complication or even death. SWAB– Cotton or piece of cloth used to clean the abdomen.
Euthansia (Mercy Killing): “Producing painful death of a person suffering
from hopeless, incurable & painful disease.”
Types of Euthansia:
1. Active: Act of commission; means giving large dose of drugs. 2. Passive: Act of omission; means discontinuing or not using life sustaining
measures like removal of ventilator, resuscitation. 3. Voluntary: At the will of patient. 4. Involuntary: Against the will of the patient, when person is incapable of
making decision, like irreversible coma. 5.
Consent: Means voluntary agreement, compliance or permission.
Types of Consent:
1. Expression:
a- verbal, b- written
2. Implied/ Informed:
Put his arm in front of you so you can inject etc.
Rules of Consent:
1- Consent is necessary for every medical examination.
2-Oral consent should be in presence of 3rd party, like nurse.
3-Expressed consent required, if any procedure done beyond routine physical
examination, like blood transfusion, operation.
TRAUMATOLOGY
Traumatology: it is knowledge of trauma or injury.
Trauma: it is illegal harm to any person in body, mind, repute or property.
In Body: Physical Trauma
In Mind: Psychological Trauma
Wound: it is discontinuation or disruption of any tissue of body, every wound is
trauma but every trauma is not wound as trauma can be to mind, repute or
property.
Hurt: is bodily pain, disease or infirmity caused to any Person!
Assault: is to threat or attempt to apply force.
Battery: actual application of force.
Homicide: Killing of a human by conduct of another.
Suicide: is self-murder. It is an unlawful act.
Accident: event neither expected nor desired or designed.
Classification of Injuries:
1. Mechanical injuries by physical violence.
2. Thermal injuries by heat or cold.
3. Chemical injuries
4. Electrical injuries
5. Firearm injuries
1. MECHANICAL INJURIES:
The injuries inflicted by mechanical force are generally divided into those caused
by blunt force and those due to sharp force. Injuries may be single or multiple.
There may be more than one type of skin injury to the body and they may be
localized or widespread. The effects of the injury on the body may be local (e.g. a
bruise on the breast), systemic (e.g. shock following a stabbed blood vessel in the
leg) or as a result of complications (e.g. kidney failure due to shock and infection).
It should be noted however, that the absence of external injury to the skin or
genitalia does not exclude the possibility of serious injury to the internal organs.
Bruises or Contusions: A bruise is an area of skin discoloration. A bruise occurs
when small blood vessels break and leak their contents into the soft tissue
beneath the skin. In bruise external surface may remain intact, only subcutaneous
surface is involved.
Factor modifying appearances of bruises are:
1. Vascularity: greater the vascularity greater will be the size of bruise.
2. Force: greater the striking force greater will be the bruise.
3. Age: old age people bruise easily.
4. Sex: females especially obese one bruises easily
5. Area: bony sites and lax skin bruise easily, while abdominal wall and scalp
does not bruise easily. Scalp of newborn bruise easily.
6. Texture: thin and delicate skin bruise easily.
7. Physical condition: Obese and unhealthy persons bruise easily.
8. Diseases: persons with coagulation disorders, liver and renal failure bruises
easily.
9. Complexion: bruises are well marked on persons with fair complexion.
10. Blisters: due to oblique blow or fractures of underlying bone blisters are
formed over bruise.
Age of Bruise:
Color changes:
1st day: red
2nd day: violet
3rd day: bluish black
4th day: livid red
5-6th day: greenish
8-12th day: yellowish
13-15th day: normal
There are no bluish or greenish stages in subconjunctival hemorrhage.
Medico legal Aspects:
1. identification of objects causing injury
2. degree of violence
3. time of injury
4. Purpose of injury: around neck=throttling, around nose and
mouth=smothering, on arms and face=sign of struggle, on
inner aspects of thighs and genitalia=sexual offence.
5. Is bruise true or false
6. is injury suicidal, homicidal or accidental
Antemortem Bruise Postmortem Bruise
1. Swelling is also seen No swelling
2. Color changes are seen No color changes
3. Epithelium abraded Not so
4. Margins-not shard and well define Sharp and well defined
5. It can be anywhere Occur only 2 hours after death.
True Bruise False Bruise
1. Color changes are seen No color changes
2. Margins are well defined Not defined
3. Swelling is seen No swelling
4. Extravasation of Blood Not present
5. Blood Coagulation No coagulation
6. Occur on any part Only at accessible is seen
7. No itching Itching is present
8. Area is not corroded Irritation corrosion present
9. Chemical tests are negative Positive
10. Blood is present in true bruise Serum is present in false bruise
Abrasion: An abrasion is a superficial injury to the skin in which the outer layer of
the skin is scraped off.
Examples include a scratch from a fingernail, imprint caused by a belt buckle,
grazing of the skin caused by dragging the body over a rough surface and the
impression around the neck caused by a cord or rope used in strangulation.
Abrasions allow inferences to be drawn about the nature and shape of the object
(e.g. a belt buckle); the time of the injury (e.g. recent or healed); the type of the
assault (e.g. abrasions on the neck and genitalia in rape strangulation); and the
cause and mechanism of death (e.g. strangulation)
Lacerations: A laceration is a wound with irregular edges which results from the
application of blunt force which causes tearing or splitting of the skin. Lacerations
also allow inferences to be drawn about the nature and shape of the object; the
time of the injury (e.g. recent, healing or healed); and the cause and mechanism
of death (e.g. head injury caused by beating with a stick)
Incised wounds (cuts): An incised wound is a superficial wound in which the size
of the wound on the surface is larger than the depth of the wound (e.g. wound
caused by a razor blade).
Hesitation or Tentative Cuts: These refer to preliminary cuts made by a person
intending to commit suicide by a cutting instrument- before gathering courage to
make a final incision.
There are: Small, multiple, superficial, merge with main incision, if wound tails
towards right person is right handed, if wound tails towards left person is left
handed.
Medico legal Aspect:
Homicidal are deep and on any part of the body but suicidal are many and on
accessible parts of the body.
Stab/Penetrating incised wounds: In a penetrating incised wound the depth of
the wound is greater than the surface length of the wound (e.g. stab wound
caused by a dagger).
Characteristics:
Wound of entry: It is bigger than the exit wound, margins of the entry wound are
clear cut and inverted.
Wound of exit: it is smaller than the entry wound, margins are averted, it is seen
in perforating not penetrating stab wounds.
Fabricated/Self inflicted/Self suffered Wound: Wound produced by a person on
his own body or caused by another person in agreement with him (self suffered)
Objectives:
2. To support false charge
3. To escape military service
4. To destroy evidence of certain injury
5. To show self defense
It is revealed by careful examination. Examination of clothes is very important.
These injuries are on assessable parts of body, half heatedly inflicted and not on
vital parts.
Defense Wounds: Wounds sustained by a person as a result of his spontaneous
reaction to protect himself, when attacked.
Causes of Death from wounds:
Primary or intermediate causes: Secondary or indirect causes:
Excessive bleeding Infection
Injury to vital organs Thrombosis
Neurogenic shock Secondary shock Embolism Supervention of new disease
Crush syndrome Acceleration of preexisting disease Operational disorders
(i) High dose, Long term exposure (x-rays, g-rays, UV):
- Cataract.
- Sterility.
(ii) Low dose, Long term exposure exposure (x-rays, g-rays, UV rays):
- Aplastic anemia.
(iii) Long term exposure to beta rays:
- Chronic radio-dermitis.
- Hyper-pigmentation.
- De-pigmentation.
- Atrophy.
- Squamous cell carcinoma.
- Basal cell carcinoma.
(iv) Cancers due to radiation exposure:
- Skin- squamous cell carcinoma and basal cell carcinoma.
- Bone tumour.
- Leukemia.
- Lymphoma.
- Lung cancer.
- Thyroid carcinoma.
(V) Pre-natal radiation effect:
- Various types of congenital deformities.
Acute Radiation Syndrome: A single exposure of a large dose of over 100 rads
penetrating radiation on the whole body within 1 to 2 days, results in a
progressive series of signs and symptoms known as acute radiation syndrome.
The sign and symptoms are as follows:
- Vomiting and Nausea with diarrhea and abdominal pain.
- Headache, erythema of skin and conjunctivitis.
- Loss of hair and fine desquamation of skin.
- Severe hematological damage-aplasia of bone marrow, agranulocytosis,
thrombocytopenia resulting in hematological disturbances.
SPECIAL TRAUMA:
1. FIREARM INJURIES:
Mechanism of firearms:
I. The firearm is actually fired when the trigger is pulled.
II. The trigger has a firing pin or hammer who strikes the percussion cap at
base of the cartridge.
III. The priming of percussion cap is detonated by the striker or firing pin.
IV. The explosion of primer ignites the propellant powder in the cartridge case.
V. This result in evolution of relatively large volume of gases which is under
high pressure.
VI. This volume of gas expands and causes the cartridge case to swell.
VII. Consequently the hold of bullet is released.
VIII. Bullet is forced out of the muzzle with certain of velocity.
IX. The bullet is accompanied by the blast of highly compressed gases, smoke,
flames, particle of partially burnt or unburnt grains of powder, fragments of
metal, grease, wad etc.
Firearm wounds: Every firearm is a punctured wound, with a wound of entrance,
progressing deep inside, presenting the track of bullet and some time making the
wound of exit.
Case of short guns: Up to some distance the pellets make a single path then due
to dispersion of pellets, multiple small wound of entrance are produced around
the main wound of entrance.
-The margin of main wound is very irregular, ragged and inverted.
-Some of the peripheral pellets may just strike the skin without entering the
depth of the tissue.
-Beside this affects of firearm hot gases, smoke, unburnt powder, semi burnt
powder may be found around the wound of entrance.
-Beside this the wad may trailed to a certain distance and makes the abrasions
around the wound of entrance in case of shot from a near distance.
Injuries due to riffled firearms: There is a single punctured wound of entrance. It
travels deep inside the body injuring organs in its tract and sometimes makes a
wound of exit.
Wound of Entrance: The wound of entrance is circular when the bullet strikes the
surface perpendicular. It is oval when the bullet strikes the body at an angle.
-The wound is smaller when the firing is from close range except in contact shots.
It is slightly larger when firing is from long distance.
-There may be some abrasions and contusions of the friction area around wound
of entrance by the bullet, is called as abraded or contused collar.
-Around the abraded or contused collar there is a dirt or grease collar made by a
metallic dust and grease from the surface of the bullet.
-Grease collar should not be confused with corona, which is blackish circular zone
around the wound caused by smoke in case of short from a near distance.
-The wound of entrance is inverted and no protrusion of fat through the wound.
Depth and track of wound:
-After entering the body the bullet may run in a straight course or it may get
reflected and takes a different course due obstruction by the tissue and mostly by
bone splinter from the fractured bone may show different track and separates the
wound of exit.
-The bullet may be lodged inside the bone or organ; some bullets may be
reflected from the bone and may come out from the same wound of entrance.
-If the body covered by cloths, the fabrics torn out may be pushed inside wound
by the bullet.
-If the body covered by cloths, the fabrics torn out may be pushed inside wound
by the bullet.
-In bullet injury there may be less hemorrhage around the wound of entrance
Wound of Exit:
-Exit wounds are larger than the corresponding entrance wounds the skin edge
averted with protrusion of fat through the wound.
-The margin is irregular.
-Hemorrhage is more near the wound of exit.
-When the site of exit wound is in contact with the hard surface like wall then the
margins are abraded, so called as shored exit wounds.
-There may be multiple exit wounds due fragmentation of bullet or emergence of
fractured bone pieces.
Case of skull:
Punched in: wound of entrance.
Punched out: wound of exit.
Special features of bullet wounds:
I. Ricochet Bullet: It is the bullet which by striking the body strikes some hard
surfaces like wall where it get bunched or reflected to take a different track
and then strikes the body of the person.
-Such a deform ricochet bullet causes more extensive wound of the
entrance, but its power of penetration is reduced.
II. Tandem Bullet (Piggy tail Bullet): First bullet which has been stuck inside
the barrel may be fired out when firing the second bullet and both the
bullets will enter the body at the same wound of entrance. When
postmortem is done there may be two bullets with only one wound of
entrance.
III. Dum Dum Bullet: The bullet splits when it strikes the body is called dum
dum bullet.
IV. Presence of more than one bullet in body: It may be tandem bullet. Two
bullets of two rapidly successive firing.
V. Single wound of entrance with more than one wound of exit:
VI. With more than may one wound of entrance there may be one bullet
present in the body: Bullets getting into the arm and exiting from the
medial aspects of arm and again entering the chest with another wound of
entrance.
VII. Multiple wound of entrance with multiple wounds of exit with no bullet
found inside the body: Entering from outer aspects of chest and exiting
from other aspects of chest then entering from medial aspects of arm and
exiting from the lateral aspects of the arm.
VIII. Kennedy Phenomena: When during autopsy it is difficult to distinguish
between firearms entry wound and exit wound.
American president PJK Kennedy sustained injury on neck, bullet entered
from back of neck and exit was from the front through trachea. The exit
wound was of small size difficult to say that was it entry or exit or another
entry from front. In fact the exit wound was small as the tight collar
supported the neck tissue. As he was taken to hospital, attempts were
made to save his life and during surgical manipulation it further became
difficult to distinguish between entry and exit wound.
Medico legal Aspects of Firearm Injuries:
1: Nature of death due to firearm injury:
A= Suicidal:
i. Located more approachable parts of the body.
ii. Usually use of hand rest weapon.
iii. Often the entrance wounds are contact wounds with presence of muzzle
mark around the wound of entrance.
Iv. The gun may be hold in a tight grip( state of cadaveric spasm).
v. Finger prints of a suicidal person may be in the trigger of the firearms.
B= Homicidal:
i. May be at anywhere in the body with contact, near shot or distant shot of
the wound.
ii. May be both short barreled or long barreled guns are used.
iii. The weapons are usually absent at the spot.
iv. Spot may be approachable to others. May be fingerprints of the
assailants (if weapon present at the spot).
C= Accidental:
i. May be due to wrong aiming or missing the target.
ii. May be due to playing with loaded guns or cleaning the loaded guns.
2: The direction of firing:
The direction from where the firearm has been used can be easily
understood from:
i. Finding at the margin of wound of entrance: circular or oval.
ii. From the direction of track of the wound inside the body.
3: Distance of firing:
A= In case of shot gun firing:
i. Presence of fire, smoke, partially burnt or un burnt gun powder.
ii. The disc and wad causing abrasions at the wound of entrance.
iii. the diameter of the area of dispersion of pellets over the body.
iv. Impression of the muzzle in case of contact wounds.
B= In case of bullet injury (rifled guns):
i. Effects of fire, smoke, burnt and un burnt gun powder , when firing is
from short distance.
ii. Wound of entrance smaller, short distance.
iii. Wound of entrance slight bigger, long distance.
iv. Impression of muzzle, contact firing.
4: Identification of firearm weapon used:
This can be done from following;
A- Comparative study of the bullet recovered from the dead body and the
test bullet fired from the suspected guns, two types of markings are usually
available in used bullets.
Primary markings:
They are the marks engraved on the surface of the bullet due to lands and
grooves present on the inner surface of the barrel of the riffled firearms.
Secondary markings:
These marks on the surface of bullets caused due to certain individual
features of the inner surface of the barrel like minor projections or
elevations or depressions which are specific of a particular gun and not
common to all guns even the same make.
B= Examination of the suspected gun:
Evidence of the recent use of the guns can be established by physical and
chemical exam of the swab from the chamber and bore of the guns.
5: Identification of the assailants:
i- Dermal nitrate or paraffin test:
It is a lab test. If nitrogenous material is present when swab of the accused
person’s fingers is taken (diphenylanine)
ii. Harrison and Gilroy’s test:
It is done for lead, antimony or barium if present from the swab of accused
fingers.
Done by spectro-photometery, atomic absorption spectroscopy.
Also by Neutron activation Analysis.
Causes of death in case of firearm injury:
-Hemorrhages.
-Shock injuring vital organs.
-Fats and air embolism.
-Asphyxia.
-Infections.
-Lead poisoning
Souvenir Bullet: A bullet accommodated in the body with healing of injured
tissues around it and in the track of bullet is called as souvenir bullet.
Difference between the wound of entrance and wound of exit:
Entrance Wound Exit Wound
1- Size: smaller 2- Margin: inverted 3- Blackening, burning: present. 4- Abraded or confused and greeze color: present. 5- Foreign fabrics: enters the wound. 6- Hemorrhages: less. 7- Dispersion of pellets in short gun cases: present. 8- Protrusion of fats: absent. 9- Bright redness due to the formation of COHb: present.
1- Larger. 2- Averted. 3- Absent. 4- Absent. 5- Nothing such seen. 6- More. 7- Absent. 8- Present. 9- Absent.
10- Metallic ring shadow on x ray: present. 11- Impression of muzzle: present in contact shot. 12- Bursting effects: present.
10- Absent. 11- Absent. 12- Absent.
2. Blast/Explosion injuries:
These are due to house made bombs, explosions of shells, torpedoes, and mines
etc in wars and as well as in peace and also in cases of terrorism.
Explosion is mainly accompanied by blast waves, flame, fragments, secondary
missiles, fragments of vehicles, and falling buildings.
There definite waves are recognized:
a. Wave of positive pressure.
b. Wave of air displacement.
c. Wave of negative pressure.
Common types of explosives:
Nitroglycerine (40% dynamite)
PETN
TNT (2:4:6 Trinitrotoluene)
RDX (rapid detonating explosives)
Effects on Victims:
-Bodies are blown into pieces and instantaneous death occurs.
-Flame causes 1st, 2nd and 3rd degree burns.
-Sound effect may cause the rupture of the tympanic membrane.
-Blast waves causes rupture of abdominal organs, pneumothorax, ruptured
stomach and bowl may be the other effects from explosions.
-Embolism in circulation.
Medico-Legal Aspects:
Try to count number of victims and try to put pieces of same person together.
Perform precipitin test to distinguish between the pieces of human and animal
bodies.
3. Communication and Transportation Injuries:
These injuries include:
a. Vehicular Injuries (Road Traffic Accidents)
b. Railway Injuries
c. Aircraft Injuries
Road Traffic Accidents (RTA):
Causes of RTA:
1. Fault of the victim.
2. Fault of the driver.
3. Fault of the Vehicle.
4. Fault of another vehicle, not involved in the accident.
5. Bad road condition.
6. Wrong signaling.
Investigation of RTA:
The investigation of RTA involves the following purposes:
1. To identify the cause of death.
2. To allow adequate compensation to the victim, if he/she is alive or dead.
3. To punish the offender, if offence is involved.
4. To search guidelines towards prevention of such future accidents.
Thus the investigating team should involve Investigating Police officer,
automobile expert and Medico-legal expert.
Thus, the investigating team should investigate the following:
1. Collection of history.
2. Examination of the deceased or the injured.
3. Examination of the vehicles involved in the accident.
4. Examination of the spot or place of occurrence of the accident.
Injuries and their Interpretations in Road traffic accidents.
RTA injuries are blunt force injuries with force-full impact.
According to their mode of production, they have 3 distinct types:
1. Primary impact Injuries.
2. Secondary Injuries.
3. Secondary Impact Injuries.
1. Primary Impact Injuries:
-It is caused by vehicle.
-Caused when the vehicle hits the victim e.g. pedestrian, for the first time, to
knock him down. Thus the injuries may bear the design of the part of vehicle
causing the injuries in the form of Imprint abrasion or patterned bruises.
-The marks on the body of the victim by the part of vehicle may give an idea
about the height of the vehicle.
2. Secondary Injuries:
-It is caused by the roadway, pavement or other objects like trees etc.
-These injuries are sustained by the victim after being knocked down by the
vehicle, due to fall and friction or impact with the ground.
-So, on examination, sand, soil, or gravel on the injuries area helps to link the
place of occurrence.
-Grazed abrasion and Stretched laceration are most common due to friction with
the ground.
3. Secondary Impact Injuries:
-It is due to running over or dragging by the vehicle.
-These injuries are as a result of impact between the body and the vehicle for the
second time.
-When after primary impact, the victim thrown forward and falls on the ground
and if the vehicle is still in motion, then the wheels of the vehicle will run over the
victim. Hence secondary impact injuries bear the tyre marks of the wheels.
-Avulsion laceration is the most frequent injury caused due to run over by the
vehicle.
Post-Mortem Examination:
It includes examination of dead victims for:
1. The body should be examined carefully for abrasions, bruises and
lacerations with their size, numbers and placement.
2. The clothes if available should be examined for tears, grease marks,
blood stains, soil or mud stains etc.
3. Internal injuries should be noted with presence of any glass fragment or
metals, paint flakes to compare with the vehicles.
4. Tyre marks, if presents should be noted.
5. Blood should be taken for estimation of alcohol, or any sedative drugs if
taken during driving.
Railway Accidents:
Railway injuries may be accidental or suicidal.
Fatal railway injuries may be sustained in the following ways:
-While walking along the rail or track.
-While crossing the rail or track.
-When a person is pushed suddenly in-front of a running train.
-When a person lies down on the railway track for a suicidal purposes, when the
train is coming.
-When a person accidently falls or intentionally jumps or is pushed from a running
train.
-When the head or some part of the body is extended out of the door or window
of a running train.
-When two train coming from the opposite direction collides.
-When the train is de-railed.
-When there is an outbreak of fire in a running train.
-When the passengers standing on the roof of train are electrocuted or struck
against and overhead structure or a over-bridge.
-Identification of a victim may become very difficult due to gross mutilation of the
body.
Aviation Accidents:
-Most challenging problem for identification of the victims.
-The bodies are often with gross mutilation or burnt that identification is nearly
impossible.
-Sometimes, the pocket articles, passports, letters, photographs, tattoo marks,
dentition, if un-burnt, may help for identification of victim.
-Now a days, DNA test is the mode of identification is such aviation accidents.
TOXICOLOGY/POISONING
Toxicology is a science dealing with properties, action, toxicity, fatal
dose, detection, estimation and treatment of poisons.
Forensic toxicology deals with the medical and legal aspect of the
harmful effects of chemicals on human being.
Toxicology refers to toxins produced by living organism which are
dangerous to man. Like poisonous plant, venom of snake, spider,
scorpion.
Poison is a substance, which if introduced in living body, or brought in
contact with any part through, will produce ill health or death, by its
constitutional or local effects or both.
Some poisons are harmless in small quantity but produce death if large
quantity is used.
Property of ideal homicidal poisons:
1. Cheap
2. Easily available
3. Colorless, odorless, tasteless.
4. Highly toxic and very small fatal dose.
5. Sign and symptoms should resemble of natural disease.
6. There should not be any antidote.
7. There should be no postmortem changes.
e.g. arsenic, aconite are commonly used homicidal poison.
Property of ideal suicidal poisons:
1. Cheap
2. Easily available
3. Tasteless or pleasant taste.
4. Highly toxic.
5. Can be taken with food or drinks.
6. Capable of producing painless death.
e.g. Organ phosphorus compound (OPC), endrine are commonly used in
rural area. Barbiturates, potassium cyanide and diazepam in urban area
are used as suicidal poison.
Classification of poison according to symptoms they produces (mode