FMGE 2024 — Forensic Medicine
4 Previous Year Questions with Answers & Explanations
During measurement of a rifled barrel weapon, the caliber depends on?
During the forensic examination of semen from a rape victim, the identification of distinctive yellow needle-like crystals raises attention. What is the specific test employed to confirm the presence of semen?
A person who was mentally unsound at the time of committing a crime is exempt from liability if they were unaware of the nature of their actions or its consequences. What is this principle called?
A family died in a closed room that was full of smoke from a wood fire. Which of the following findings is likely to be seen on the body?
FMGE 2024 - Forensic Medicine FMGE Practice Questions and MCQs
Question 1: During measurement of a rifled barrel weapon, the caliber depends on?
- A. Distance between two opposite lands (Correct Answer)
- B. Distance between two opposite grooves
- C. Mass and velocity
- D. Number of lead pellets
Explanation: ***Distance between two opposite lands***- The **caliber** of a rifled firearm refers to the nominal diameter of the gun barrel's bore, measured between the two opposing **lands**.- The land is the raised shoulder between the grooves in a rifled barrel; measuring the distance across the lands provides the smallest internal diameter of the barrel.*Distance between two opposite grooves*- This measurement corresponds to the **groove diameter**, which typically determines the required diameter of the projectile (the bullet).- While related to bullet fit, the distance across the grooves is generally greater than the caliber and is not the accepted definition of the weapon's caliber.*Number of lead pellets*- The number of lead pellets (or 'shot') is relevant to **shotguns** (which typically have smooth bores), not rifled weapons.- This measurement relates to the load of a shell and the **gauge** of a shotgun, not the caliber of a rifled barrel weapon.*Mass and velocity*- **Mass** and **velocity** are dynamic characteristics of the projectile (internal ballistics), determining the energy and momentum of the shot.- These parameters are influenced by the cartridge load but do not define the fixed mechanical dimension (**caliber**) of the barrel.
Question 2: During the forensic examination of semen from a rape victim, the identification of distinctive yellow needle-like crystals raises attention. What is the specific test employed to confirm the presence of semen?
- A. Acid phosphatase test
- B. Barberio test (Correct Answer)
- C. Papanicolaou smear
- D. Florence test
Explanation: ***Barberio test***- This test is a classical **presumptive chemical test** for semen, based on the detection of **spermine**, a polyamine found in high concentration in seminal fluid.- It involves reacting the semen extract with **picric acid**, which leads to the formation of characteristic insoluble **yellow needle-like crystals** known as **spermine picrate**.*Acid phosphatase test*- This is a highly sensitive **presumptive test** for semen which detects the high concentration of the enzyme **prostatic acid phosphatase (PAP)**.- A positive result is indicated by a **rapid color change** (often purple or reddish-purple), not the formation of specific yellow crystalline structures.*Papanicolaou smear*- The Pap smear is fundamentally a **staining technique** (cytological stain), mainly used to visualize and identify **epithelial cells** and **spermatozoa** under a microscope.- While it is used on swabs from rape victims to definitively identify the **sperm cell heads**, it is not a chemical test that yields distinctive yellow crystals.*Florence test*- The Florence test is another traditional **presumptive test** that detects **choline**, another component of semen.- It reacts with potassium iodide and acetic acid to form **choline periodide**, resulting in dark **brown, rhombic**, or needle-like crystals, which are distinct from the yellow crystals of the Barberio test.
Question 3: A person who was mentally unsound at the time of committing a crime is exempt from liability if they were unaware of the nature of their actions or its consequences. What is this principle called?
- A. Durham's rule
- B. Currens rule
- C. Irresistible impulse test
- D. McNaughton rule (Correct Answer)
Explanation: ***McNaughton rule (M'Naghten rule)*** - This is the **correct answer** as it establishes the legal test for insanity defense based on whether the accused was aware of the **nature and quality of the act** or knew it was **wrong** - Originated from the **1843 case of Daniel M'Naghten** in England and remains the most widely used insanity defense standard - Key principle: A person is not criminally responsible if, at the time of committing the act, they were **laboring under such a defect of reason from disease of the mind** as to not know the nature and quality of the act or that it was wrong - Applied in **India under Section 84 of the Indian Penal Code** *Durham's rule (Product test)* - This rule states that an accused is not criminally responsible if the unlawful act was the **"product of mental disease or defect"** - Much broader than M'Naghten rule - Used briefly in US courts but largely abandoned due to being too broad *Currens rule* - This test focuses on whether the defendant had the **capacity to conform their conduct** to the requirements of law - Emphasizes volitional control rather than cognitive understanding - Less commonly used standard *Irresistible impulse test* - This is a **supplementary test** that asks whether the defendant could **control their actions** even if they knew they were wrong - Addresses volitional incapacity rather than cognitive incapacity - Does not match the question's emphasis on "unaware of nature or consequences"
Question 4: A family died in a closed room that was full of smoke from a wood fire. Which of the following findings is likely to be seen on the body?
- A. D. Brown colored pigmentation
- B. A. Cherry red hypostasis (Correct Answer)
- C. B. Cyanosis
- D. C. Blackish discoloration
Explanation: ***A. Cherry red hypostasis*** - Carbon monoxide (CO) from incomplete combustion of wood binds to hemoglobin with ~240 times greater affinity than oxygen, forming **carboxyhemoglobin (COHb)** - COHb has a characteristic **bright cherry-red or pink color**, which manifests as cherry-red hypostasis (post-mortem lividity) and pink coloration of internal organs - This is the **pathognomonic post-mortem finding** in CO poisoning deaths - Levels >50% COHb are typically fatal *B. Cyanosis* - Cyanosis (bluish discoloration) occurs when deoxygenated hemoglobin exceeds 5 g/dL - **Not seen in CO poisoning** because carboxyhemoglobin remains bright red, giving a pink appearance rather than blue - The victim may appear "healthy" or flushed despite being dead *C. Blackish discoloration* - Not a characteristic finding in CO poisoning - May be seen in putrefaction or certain chemical poisonings, but not acute CO exposure *D. Brown colored pigmentation* - Not associated with CO poisoning - Brown discoloration might suggest methemoglobinemia or post-mortem changes, but not CO toxicity