Forensic Medicine & Toxicology notes for competitive exams

Forensic Medicine & Toxicology notes for competitive exams

Dr Anusree Prakash  MD(Hom)

1. Child at the age of  7 has 20 teeth.

2. Ductus arteriosus completely obliterates in 6-12 days

3. Other names of opium — are Casoomba. Madak. Chandu

4. Smokeless gunpowder  is composed of  Nitrocellulare

5. Provisional callus form in fracture by 7days

6. Pond fracture seen in children

7. In frostbite, skin becomes black & hard within 2weeks

8. Average fatal period of  Cu poisoning is l-3davs

9. Marbling is seen at 36hrs

10. Choking is done in Shot

11. Callus becomes thick & hard like bones within 3months

12. Indian lunacy act was passed in 1881

13. Mental retardation is when a person has IQ below 70

14. Upper limit for safety of  Co in air is .01%

15. Narcotic d and psychotropic substance act was passed in the year 1985

16. Maximum congestion is seen in strangulation

17. Best specimen bone for sex determination is  pelvis

18. In rigor mortis, muscles stiffen & shorten

19. Minimum  age for MTP is l8yrs

20. Triage is associated with Warfare injuries

21. Velvety appearance of stomach is seen in Ars   poisoning

22. Gettler’s test is positive in drowning

23. Criminal negligence includes Res ipsa Loquitur, Law of vicarious liability. Novus Actus Interveniens

24. Cyanide poison acts by inhibiting cellular respiration

25. Crocodile skin appearance is seen in th vo1ta bums

26. Stomach in carbolic acid poisoning is leathery stomach

27. Haemoglobinuria is seen in CuSO4 poisoning, snake venom, C.Welchi infection

28. Brachicephalic is due to the fusion of Coronal suture

29. Black gunpowder has Sulph, charcoal. Pot. Nitrate

30. Opium poisoning produces slow, shallow respiration

31. Liquid gold with ref to urine denotes the presence of heroine

32. Run amok is seen in Cocaine poisoning

33. Statutory rape is rape  in police custody

34. Pseudodementia is seen in Schizophrenia

35. Hg and phenol poisoning is characterised by proximal tubular acidosis.

36. Paris green is a stomach poison

37. Takayarma test shows pink feathery crystals

38. Oedematous lungs are seen in Organophosphorus noisoning

39. Asthma-like symptoms are seen in Organophosphorus poisoning

40. Café coronary is due to asphyxia

41. Legal age by which a foetus is capable of independent existence is 210 days

42. In deep incised wound, langer’s lines indicate gaping

43. Average fatal period of Cu poisoning is I 8-36hrs

44. Morbid jealousy is diagnostic of Cannabis poisoning

45. Age of a l6yr old female is best determined by radiograph of upper  end of radius and ulna

46. Legislation regarding insanity is Mac Daughter’s rule Duchan’s rule, Curren’s rule.

47. Paultauf’s hemorrhage occurs in drowning

48. Foamy liver and honey combing of liver is seen in Putrefaction

49. Non-poisonous salt of cyanide is Pot. ferrocvanide

50. Anterior horn cells are affected in Strychnine

51. Commonest maternal cause of abortion is Syphilis

52. A person suffering from achlorhydria may not be affected by Potassium cyanide poisoning

53. At 30% of CO conc., clinical picture looks like that of alcoholism.

54. Wt of normal uterus is 30-45g

55. Acute lead poisoning in child presents as Status epilepticus

56. Putrefaction is retarded by Carbolic acid  poisoning

57. Venom of seasnake is myotoxic

58. The first fingerprint beaureau was established in Calcutta

59. Rectified spirit is not used as a preservative in Phenol

60. Perforation of stomach is more common due to ingestion of sulphuric acid

61. For diagnosis of lunacy a person is kept under observation for 10 days

62. Metal fume poisoning is seen in chronic poisoning with Zn.

63. An elevated level of cyanide is seen in death due to thermal burns

64. Legally, abortion is termination of pregnancy before full term

65. Least toxic compound of lead is lead sulphide

66. Puppe’s rule is related to sequence of bullets

67. 20 permanent teeth & 8 temporary teeth at 11years

68. Gutter fracture is due to firearm injury

69. Detection of heavy metals is done by Harrison gillory test. Spectroscopv. Neutron activation

70. Linseed oil contains Hydrocvanic acid

71. Jet-black tongue is seen in Cocaine poisoning

72. Rigor mortis occurs first in which voluntary muscle — that of hand

73. Most specific test for Organophosphorus poisoning is RBC cholinesterase

74. Rigor mortis of foetus occurs after 7 mths of age

75. Alternate contraction & dilatation of pupil is seen in Aconite poisoning

76. Corpus delicti is essence of crime

77. In acute Ars poisoning, Ass accumulates in liver, kidney & keratin

78. Cephalic index in Indian is 70-75

79. Acid digestion test is used to detect diatoms

80. A mortis is cooling of the body

81. Livor mortis is postmortem staining

82. Stellate wound is seen in contact shot

83 Postmortem caloricity is seen in septicaemia. tetanus, strychnine poisoning. sunstroke, and pontine haemorrha

84. Cadaveric rigidity is prolonged & putrefaction is delayed in Ars poisoning

85. At the age of 9 no. of  teeth is 16

86. Jurisdiction of land comes under district court

87. Juvenile court is presided by first class magistrate

88. Weight of virgin uterus is  50g

89. H202 is used in benzide phenolphthalein orthotoludine test for blood.

90. Deep blue colour is seen in hypostasis of CO poisoning.

91. Most reliable method for alcohol estimation in blood is thin layer chromatography –

92. Raindrop pigmentation is seen in Ars poisoning

93. Rigor mortis first appears in heart, then eye

94, Cyanide poisoning antidotes are Sod. Thiosulp & amyl nitrate

95. Cage testis used for alcohol poisoning

Forensic medicine is the application of medical knowledge for the solution of legal problems.

Medical Jurisprudence means legal aspects of practice of medicine.

Inquest is the enquiry into the cause of death, where death has occurred in suspicious circumstances. It’s of  3  types:

Police inquest — Conducted by a policeman. Report is signed by him & as many witnesses as possible. Commonly used in India.

Magistrate Inquest — Conducted by a magistrate. Used in cases of death in police custody or death of a housewife within 7 yrs. of marriage.

Coroners Inquest — Was used in Metropolitan cities, like Bombay, till 1999. Coroner’s court is a court of enquiry & not of trial.

Offence may be; Cognizable (Here police officer can arrest the person without a warrant.) or Non  cognizable (Here, warrant is required.)

Courts include Criminal & Civil courts.

Criminal courts include;

Supreme court (One for each country) — It’s purely appellate. High court (One for each state)  It can try any case & give any punishment according to the law.

Sessions court (One for each district) — It can give any punishment, but a death sentence must be confirmed by the high court,

Magistrates — Can give a punishment of imprisonment upto 7yrs. And a fine of upto Rs.5000/-

Subpoena (Summons) – Is a written document issued by the court to attend the court for giving evidence on a particular date & time.

Conduct money — Is a fee paid to the witness for serving the summons, given in civil cases.

Perjury — Is defined as willful giving of false evidence by a witness under oath. It’s defined in IPC 191 & its punishment is given in IPC 193 as imprisonment up to 7yrs.

Documentary evidence includes:

  • Medical Certificate
  • Medicolegal Reports
  • Dying Declaration .— It’s a written or oral statement of a dying person. It must be recorded by a magistrate or a doctor with the signature of the doctor & 2 witnesses.
  • Dying Deposition — It recorded in the presence of the accused or his lawyer. It’s superior to dying declaration.

Witnesses are of 3 types: Common witness, Expert witness & Hostile witness.

Serious Professional Misconduct (Infamous Conduct) — Is a conduct considered disgraceful or dishonourable by medical practitioners.

Penal Erasure (Professional death sentence) — If the doctor is guilty of serious misconduct, he loses all the privileges of a registered medical practitioner.

Offences contained in the warning notice;

  • Issuing false certificates
  • Performing illegal operations or criminal abortions

Dichotomy (fee – splitting) .— Receiving or giving commission to a professional colleague or a chemist, dentist, etc.

Covering — Assisting a person with no medical qualification to attend, treat or perform an operation.

Advertisement — Repeated advertisement in newspapers by a medical practitioner.

Professional secrecy — The secrets regarding a patient can only be revealed for;  protection of the individual

Protection of the community

Interest of justice

Professional Negligence comes under IPC 312, 304A. It’s defined as the lack of reasonable care or willful negligence of a doctor resulting in the injury or death of a patient. It includes:

Tort- A civil wrong

Res Ipsa Loquitur — The thing speaks for itself

Novus Actus Interveniens — Unrelated action intervening  Eg; If a doctor leaves a swab or instrument in the abdomen after a surgical operation.

Criminal Negligence — Is dealt with in mc 304 A. According to this a doctor can be punished for upto 2 yrs.

Contributory Negligence — If an injury is produced by the combined negligence of the doctor & patient, it’s not considered as an offence.

Therapeutic Misadventure — It’s a case in which a patient is injured or dies due to some unintentional act done by the doctor or hospital.

Corpus delicti (Body of offence, essence of crime) — Establishment of identity of the dead body and causing of violence in a particular way, at a particular time and place by the persons charged with the crime and none other.

The most  reliable method of identification is by Dactylography (Galton’s system)

Fingerprint system. This is also called dermatoglyphics.

Fingerprints are of 3 types:

Loop, Whorl, Arch, Composite. Of these, loop is the most common.

Race can be determined by the Cephalic index  ie, Max breadth of the skull X 100 Max length of the skull

Dolichocephalic (CI: 70— 75) Seen in Aryans. Aborigines, Negroes. Mesocephalic (CI: 75 — 80) Seen in Europeans & Chinese.

Brachicephalic (CI: 80— 85) Seen in Mongols.

Sex can be identified by examination of bones, mainly skull and pelvis. Also, by the presence of Barr bodies or Davidson bodies. Determination of sex is difficult in cases of Intersexes, (T4ermaphroditism — True & Pseudo)

Age can be determined by examination of teeth. In children the formula is 2102 and in adults it’s 2123. Temporary teeth begin to fall at 6-7 years . Mixed dentition is seen till l2yrs. of age. Gustafson’s method can be used after 21 yrs. of age, which depends on Attrition, Paradentosis, Secondary dentine, Cement apposition, and Root resorption, Transparency of the root.

Age of foetus can be calculated from rule of Hasse.

MLI of Age:

7mths — Below 7mths, a foetus isn’t viable.

7yrs. —Any act done by a child below 7yrs isn’t an offence according to

IPC 82.

Juvenile — According to Juvenile Justice Act, 1986, a juvenile is a boy below 16 yrs or a girl below 18 yrs. A juvenile can’t be sentenced to death or imprisoned.

l2yrs. — Can give consent for medical examination.

l4yrs. — A child below 14 yrs can’t be employed to work in a factory or mine.

I5 yrs. — Rape is defined as sexual intercourse even with wife under 15 yrs or with any other girl under l6yrs, even with her consent. It’s defined in IPC 375.

18yrs. — A person attains maturity on completion of 18 yrs.

A girl under 1 8yrs and a boy under 21 yrs can’t contract marriage.

The study of hair is called trichology. It helps to distinguish whether the obtained parts of body are that of an animal or human, whether of a male or female.

The study of dead bodies is called Thanatology.

Exhumation is the digging out of an already buried dead body from it’s grave.

Tests of death include Diaphanus test, Icard’s dye test, Magnus test, Winslow’s test

Post-mortem changes include:

  • Immediate changes (Somatic death) — Cessation of respiration, circulation, insensibility.
  • Early changes (Cellular death) — Eye changes, primacy flaccidity of muscles, cooling of body, postmortem lividity & rigor mortis.
  • Late changes (Decomposition & Decay)— Putrefaction, Adipocere formation, Mummification.
  • Suspended animation is a condition in which no signs of life are seen, but life continues with functions reduced to a minimum. It’s seen in newborn infants, drowning, electrocution, cholera, etc.
  • Complete stoppage of respiration &  circulation causes death.
  • Cornea becomes opaque within 2-4hrs.
  • Taches noires appears within 3 hrs. alter death.

Cooling of the body (Algor mortis) takes 24 hrs. In certain cases, temp first rises for 2 hrs. This is called postmortem caloricity & is seen in sunstroke, septicaemia, tetanus, strychnine poisoning,

Postmortem staining (Hypostasis, Cadaveric lividity, Sugillations. Vthices, Liver mortis). It usually develops within 4hrs & reaches a maximum between 6-12 hrs. It’s epidermal in situation, seen in dependent parts & uniform in colour. Postmortem staining gets fixed in 5-6 hrs. It occurs before death in cholera. It can be differentiated from bruise by incision test.

Postmortem staining has various colours in various poisonings:

  • CO — cherry red
  • HCN — Bright Ted
  • Pot chlorate — Chocolate brown
  • P — Dark brown
  • Opium derivatives — Black
  • H2S —Bluish green
  • Septic abortion — Grayish brown

Primary relaxation lasts for about 1-2 hrs. Rigor mortis is the stiffening of the muscles which affects the eyelids, neck, Iowerjaw, face, chest, upper limbs, abdomen, lower limbs, in the same order. In India, rigor mortis appears 3hrs after death & lasts for about 24-48 hrs in Winter & 18-36 hrs in summer.

Cadaveric spasm is similar to rigor mortis but usually affects only a single group of muscles. It’s important especially in drowning.

The first external sign of putrefaction is the colour change to green in the right iliac fossa. This appears in 12-18 hit in summer& in 1-2 days in winter. The first internal sign of putrefaction is the greenish discolouration below the liver. Marbling is most prominent in 36-48 hrs. Maggots appear in about 48 hrs after death. Colliquative liquefaction is seen after I week.

Taylor’s formula — A body decomposes in air twice as rapidly in air than in water & 8 times as rapidly as in earth.

Adipocere formation occurs in warm humid climate and moist damp soil, It’s formed in the subcutaneous tissues within 3 days, due to gradual hydrogenation & hydrolysis of pre-existing fat.

Mummification is the dehydration of a body, which requires from 3mths to a year. It occurs in the absence of moisture in the air.

Abrasion is a wound in which only the superficial layers of epidermis is involved. It’s bright red when fresh, within 12-24hrs, lymph & blood dries up leaving a bright scab. After 2-3 days, a reddish brown scab is formed. After 4-7 days, epithelium grows & covers the defect under the scab.

Contusion is more marked over the bones. In the l 1-2 hrs, it’s red in colour, blue in a few hrs to 3 days, bluish-black to brown on the 4 day, greenish at 5-6 days, yellow at 7-12 days & normal in 2 weeks.

Incised wound is characterised by tailing. It has length more than breadth & depth. In afresh wound, haematoma formation can be seen. After 12 hrs, edges are swollen, red, adherent with blood & lymph. In 24hrs, a continuous layer of endothelial cells covers the surface. In 36hrs, the capillary network is complete. Within 48-72hrs, the wound is filled with fibroblasts. After 3-5 days, definite fibrils running parallel to the vessels are seen. After 1-2 weeks, scar tissue is formed.

In stab wounds, the depth is more than the length & breadth.

In fractures of skull, pond fracture is seen in children, characterised by bending, rather than complete breakage.

Grievous hurt is dealt within IPC 320.

Forensic ballistics is the science dealing with the investigation of firearms ammunition & the problem arising from their use. Choking is a constricting device at the muzzle end of the shotgun.

In burns, a pugilistic attitude is taken, due to coagulation of the muscle proteins. It’s otherwise called boxer’s attitude. Fencing or defense attitude. The seriousness of burn can be calculated by the rule of nine: According to this rule, 9% of the body surface is constituted by the head & each upper limb, 9% by the front of each lower limb, 9% by the back of each lower limb, 9% by the front of the chest, 9% by the back of the chest, 9% by the front of abdomen, 9% by the back of abdomen & the remaining 1% by the external genitalia.

In electrocution, electric marks (Joule burns) are diagnostic. Here, the most common cause of death is ventricular fibrillation.

In lightening, burns occur called arborescent burns or Filigree burns (Lichtenberg’s flowers), as they resemble the branches of a tree.

A person can live for about 10-12 days without food & water. He can live with only water, without food for 6-8 weeks. In starvation death, brown atrophy of the heart can be seen in autopsy. All organs atrophy except gall bladder.

Hanging is a form of asphyxial death, which takes 3-5 m for death. It’s characterised by an oblique ligature mark in the upper part of the neck, fracture of hyoid bone, saliva is seen dribbling from an angle of the mouth. Le facies sympathetique is seen. Legal death sentence is carried out by hanging.

Strangulation is caused by constriction of the neck without suspension. Mugging is strangulation by the forearm. Bansdola is strangulation with sticks. Garotting is strangulation by twisting a lever like tourniquet. Maximum congestion & cyanosis is in strangulation. Fracture of thyroid cartilage is more common. Throttling is manual strangulation, Overlaying is a type of smothering due to compression of the chest. Burking is a method of homicidal smothering & traumatic asphyxia.

Café coronary is a condition in which a person who begins a meal suddenly becomes blue, coughs violently, collapses & dies due to asphyxia.

Drowning is another asphyxial death. Death occurs within 4-8 mm of immersion. Postmortem test for drowning is Gettler’s test. Immersion syndrome is due to vagal inhibition in drowning & not due to submersion. The most important test for drowning is the presence of diatoms in the tissues, froth in the respiratory tract & weeds in the stomach & intestine. In wet drowning, lungs are over distended and alveolar rupture occurs. This is called emphysema aquosum. In dry drowning, death occurs due to laryngeal spasm. The alveolar walls rupture due to increased pressure during forced expiration. to produce sub pleural haemorrhages called Paultauf’s haemorrhages. The body floats in about 12- in summer & 18-36hrs in winter in India.

Sexual offences are divided into 3: 1. Natural offences including rape & incest. 2.Unnatural offences including Sodomy, Tribadism, Bestiality, Buccal coitus. 3.Sexual perversions including Sadism, Necrophilia, Fetichism, Transvestism, Exhibitionism, Masturbation, Voyeurism, Frotteurism, Undinism.

Rape is sexual activity with a woman without her consent, whether it’s because she’s too young, her consciousness has been altered or it’s against her will. Rape is defined under IPC 375. Its punishment is given in WC 376. Sexual activity with a girl below l0 yrs age or l5yrs if she is his wife is considered as rape. Incest is sexual intercourse with a close blood relative.

Sodomy or buggery is anal intercourse. When the passive agent is an adult, it’s called gerontophilia. When the passive agent is a young boy, it’s called paederasty.

  1. Female homosexuality is called tribadism or lesbianism
  2. Bestiality is sexual intercourse with lower animals.
  3. Buccal coitus is also called sin of Gommorah.
  4. Sadism is sexual gratification by hurting or injuring the partner. Extreme sadism causes Lust murder.
  5. Necrophilia is sexual gratification from intercourse with dead bodies.
  6. Fetichisrn is sexual gratification by contact with articles of opposite sex.
  7. Transvestism is sexual gratification from wearing clothes of opposite sex.
  8. Masturbation is self-stimulation.
  9. Voyeurism is peeping torn.
  10. Frotteurism is contact with other persons for sexual gratification.
  11. Undinism is watching others urinate.

Tests for seminal stains include Florence test (most important test), Barberios test, Acid phosphatase test, Creatine phosphokinase test, and Ammonium molybdate test.

Battered child is one who has received deliberate injuries from parents or guardian.

A virgin is a female who has not experienced sexual intercourse. Defloration means loss of virginity.

Medical Termination Act was passed in 1971. It allows abortion upto 20 weeks. A dead born child shows rigor mortis & maceration ie, aseptic autolysis. Spalding’s sign is positive.

Tests for b]oodstains include Benzidine test, micro chemical examination, Spectroscopic examination & Serological examination. Takayama’s test & Tiechmann’s test are additional tests.

Allowable concentration of alcohol is 1.5%. Fatal dose of alcohol is I 50m1. That of methanol is 30-60m1. Formula used to calculate ethanol in body is Widmack’s formula.

Meig’s sign is seen in Ass poisoning.

McEvan’s sign in alcohol poisoning.

Magnans sign in cocaine poisoning.

Shaking palsy in mercury poisoning.

Ars poisoning is tested by Marsh test, Reinsh’ test, Opium poisoning by Macquier test, Alcohol poisoning by McEvans test.

Ideal homicidal poison is Thallium.

Commonly used poisons are Ars & Acon.

Ideal suicidal poison is Cyanide

Commonly used suicidal poison is Endrine, Organophosphorus.

Ideal infanticide poison is Opium.

Ideal rod poison is datura.

Poisoning resembling cholera is Ars.

Poisoning resembling viper bite is Rhus precatorius.

Sweet poison is Acon.

Smell of Endrine is that of kerosene.

Smell of Phos is that of garlic.

Smell of Zn phosphide is fishy or musty.

Smell of H2s is that of rotten eggs.

Smell of ethanol, chloroform, and nitrites is sweety or fruity.

Smell of HCN is that of bitter almonds.

PM staining of Phos, Cu is dark brown or yellow.

PM staining of CO is cherry red.

PM staining of cyanide is bright red.

PM staining of nitrates or aniline is chocolate brown.

PM staining in asphyxia is bluish violet.

PM staining of H2s is bluish green.

Pinpoint pupils are seen in Opium, Endrine poisoning or in Pontine haemorrhage.

Dilated pupils are seen in Datura poisoning.

Antidote of cyanide is Amyl nitrate.

Antidote of Phos is CuSO4.

Antidote of Morphine is Naloxone.

Antidote of Organophosphorus is Atropine.

Antidote of Cocaine is Amyl nitrate.

Antidote of Dicarmarol is V K.

Antidote of Oxalic acid is Calcium glutamate.

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