Silent Assassin: Poisons and their mode of action

This presentation represents:
What is poison
Classification of poison
Types of poisoning
Mode of actions
Forensic perspective of poisons
Interesting Case study : The cyanide kempamma case - the first serial killer woman who used cyanide to kill people
And a riddle related to poison - which fascinates young minds

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SAGAR, M.P.
“SILENT ASSASSINS: POISONS AND THEIR
MODE OF ACTION”
DEPARTMENT OF CRIMINOLOGY
AND FORENSIC SCIENCE
PRESENTATION TOPIC
PRESENTATION BY:
Aishwarya Jain Y23160617
Mohor Roy Y23160131
Vidya Janghel Y23160258
Ritika Singh Y23160199
Kartik Y23160094
COURSE COORDINATOR:
Dr. Devasish Bose

2. The word “ Assassins” originated from the
Arabic word - historically used for secret killers
used poison as a weapon. ‘SILENT ASSASSINS’ ? WHY ?
Poisons act quietly - no sound, no struggle -
hence the title “ Silent Assassins ”

3. WHAT WE MEAN BY
POISON ?
A poison is any substance that causes
illness, injury, or death when it enters a
living organism, whether it's swallowed,
inhaled, injected, or absorbed through the
skin. The harm can be temporary or
permanent, depending on the substance,
the amount, and the route of entry.

4. CLASSIFICATION OF POISONS

5. A. Based on nature of poison
Strong acids:
-Mineral or inorganic acids e.g. H₂SO₄ and HCl, HNO₃
-Organic acids e.g. carbolic, oxalic, acetic, salicylic
acids
Strong alkalis e.g. hydrate & carbonates of Na, K,
NH₃
Metallic salts e.g. zinc chloride, ferric chloride,
mercuric chloride, copper sulphate, silver nitrate,
potassium cyanide, chromates & bichromates
1.Corrosive

6. A. Based on nature of poison
Inorganic:
-Non-metallic e.g. P, I, Cl, Br, CCl₄
-Metallic e.g. As, Sb, Cu, Pb, Hg, Zn, Ag
Organic
-Animal e.g. snake/insect venom, cantharides
-Plant / Vegetable e.g. castor, nux vomica,
calotropis
2. Irritants

7. A. Based on nature of poison
Cerebral poisons:
Somniferous
Inebriants
Stimulants
Deliriant
Depressant
Psychotropics
Spinal poisons, e.g., strychnine
Peripheral nerve poison, e.g., curare
Cardiac poison or cardiotoxic, e.g.,
aconite
Asphyxiants, e.g., carbon monoxide
Nephrotoxic, e.g., mercury
Hepatotoxic, e.g., phosphorus
3. Systemic

8. A. Based on nature of poison e.g. food poisoning.
4. Miscellaneous

9. Homicidal poisons
Suicidal poisons
Accidental poisons
Abortifacient poisons
Stupefying poisons
Cattle poisons
Arrow poisons
Use to fabricate injury or malingering
Use to cause injury
Use for torture
B. Based on manner of use

10. C. Based on source of poison
Domestic or household
poisons
Agricultural poisons
Environmental poisons
Industrial poisons
Food and drinks poison
Drugs and medicines

11. TYPES OF POISONING

12. LOCAL ACTION
The effect occurs only at the site of application or contact
— where the poison or drug first meets the body tissue.
No absorption into the bloodstream; effect is confined to
the local area.
Example:
Sulphuric acid causing burns on skin.
Ammonia irritating the respiratory tract.
MODE OF ACTIONS
REMOTE ACTION
The substance acts at a site distant from the site of
absorption, usually after being carried by the
bloodstream.
Example:
Inhaled cyanide gas acts on tissues by interfering with
oxygen utilization.
Carbon monoxide acts on haemoglobin in the blood.
SYSTEMIC ACTION
The poison or drug is absorbed into the bloodstream and
produces effects on specific organs or systems of the
body. Targeted organ/system effects after absorption.
Example:
Mercury affects the kidneys.
Lead affects the nervous system.
Alcohol affects the brain and liver.
GENERAL ACTION
The poison or drug affects the whole body or multiple
systems simultaneously, leading to generalized toxicity.
Multiple organs or entire body systems are involved.
Example:
Arsenic and cyanide cause cellular damage.
Barbiturates depress the entire CNS.

13. FORENSIC PRESPECTIVE OF POISONS
Helps establish cause and manner of death in suspicious cases.
Determines whether poisoning was accidental, suicidal, or homicidal.
Assists in estimating time of administration and possible dose.
Provides evidence to link suspects, victims, and crime scenes.
Guides postmortem examinations and toxicological analysis.
Supports legal proceedings through expert toxicology reports.
Helps in identifying adulteration or contamination in food, drugs, or
environment.

14. Name of Serial Killer
Full Name: K. D. Kempamma
India’s first convicted female serial killer to use cyanide poison.
Timeline and Location
Place: Karnataka, India
Active Years: 1999 – 2007
Major Crime Scenes: Bengaluru, Tumkur, and nearby temple
towns.
Modus Operandi
Kempamma targeted emotionally distressed or religious
women visiting temples.
She posed as a spiritual devotee or counselor, promising rituals
or blessings to solve their problems.
After gaining trust, she instructed the victim to perform a ritual
bath and drink “holy water” or “prasad” laced with potassium
cyanide.
Victims collapsed within minutes; she stole jewelry and
valuables before leaving the spot.
CASE STUDY: The Cyanide Mallika Case

15. CASE STUDY: The Cyanide Mallika Case
Evidence Collected
Autopsy findings: Internal organ congestion, smell of bitter
almonds, rapid death symptoms — all classic signs of cyanide
poisoning.
Scene evidence: Leftover food/water, ritual items, and missing
jewelry.
Chemical analysis: Traces of cyanide (KCN) found in viscera
samples sent to the Forensic Science Laboratory (FSL),
Karnataka.
Arrest and Investigation
Arrested in 2008 while attempting another similar crime.
Confessed to six murders between 1999 and 2007.
Police recovered stolen ornaments and cyanide packets from
her home.
Verdict and Punishment
Convicted under Section 302 (Murder) and Section 394
(Robbery) of IPC.
Sentenced to death, later commuted to life imprisonment.

16. I SHINE LIKE SILVER BUT BRING NO GRACE,
I ATTACK YOUR BRAIN AND SLOW YOUR PACE.
FOUND ONCE IN PAINTS AND FACTORY AIR,
IN BONES AND BLOOD, I QUIETLY STARE.
WHO AM I — THE METAL THAT MAKES MINDS FADE?

17. THANK
YOU

18. REFRENCES