SYWTBA: Become a Forensic Toxicologist


So you want to be a forensic toxicologist? Read part four of our comprehensive guide to getting ahead.

In India, a wealthy victim was killed when a murderer pricked his flesh with a pin as he passed by on a train platform. The victim’s jealous  step-brother, who had been travelling with him and who had hired the pin-pricker, rubbed plague germs into the bleeding wound in the pretense of giving him first aid. The step-brother had been researching bacillus cultures in a lab in Bombay. This complicit murderer had it all: a money motive, access to rare dangerous germs and the knowledge to use them. He just wasn’t as smart as he thought he was. The case was solved by careful detective work based on forensic toxicology conducted by William Wolf in 1935.

There is a curious hope by many would-be-murderers that a fatally toxic method of killing someone is available, and that by using such a poison, the perpetrator will not be caught. Therein lies the challenge: for criminals, it is the search for the perfect solution. For forensic toxicologists, it is the search for the signature, the microscopic identifiers that recognize the ‘murder weapon’, the ability to match it to a crime scene object and thereby incarcerate the perpetrator.


Lab geek and courtroom hero.

A toxicologist performs scientific tests on human cells, body fluids, tissue samples and stomach contents to identify foreign substances present in the human body. A forensic toxicologist has further responsibilities: his or her work must be meticulously recorded and follow accepted procedures using viable samples for evaluation. The tissue or blood evidence must be carefully controlled and follow police chain of custody rules. The forensic toxicologist will consult with colleagues in the crime lab to share clues that will ultimately lead to the capture of a bad guy, and then will be required to testify in a court of law, providing expert testimony while explaining complex methodologies that a judge and jury must understand.

Most of the work a forensic toxicologist does will be in a lab. Using highly sophisticated instruments, following precise methodologies, and controlling chemical regents by temperature, reaction time and solution, the expert researcher will find anomalies and identify them. Then, a determination must be made to understand the impact of this found foreign substance on the body.


Cat and mouse game: forensic investigator and perpetrator, or vice versa?

Were high levels of arsenic present? This is obviously poisoning, and the detectives can be told to look for a source. They will bag, tag and bring in glasses, food and drink from the crime scene to be matched to the body samples. Carbon monoxide in the blood? The detectives will want to look for a source — perhaps in the air handling system.

Therein is the key to this elite and dangerous game of cat and mouse.  Literally, hundreds of ordinary objects can be a carrier for a poison: food, water, wine, beer, chewing gum, pills, and even medicines of all kinds. Poisons that can be absorbed through the skin have been smeared on hand rails, walking sticks, steering wheels. It is the task of the scientific investigator to discover if a poison was used, what impact it had on the body, which element is present and how it was administered.  The results will come from analytical chemistry. Poisons travel in a living body, so traces will be found in the victim’s flesh, blood, brain or even in the viscera.


Stab marks on the cellular lever: broken red cells.

Poisons leave clues to give a toxicologist a direction in which to investigate. Blue lips could indicate carbon monoxide poisoning. The presence of organophospate — a strong insecticide — also turns lips and nails blue, but has additional indicators.  Strychnine causes violent muscular contractions. Curare, the infamous arrow poison of South America is supposed to be traceless, but it causes paralysis of most muscles except the heart, and once those symptoms are reported, a test for curane can reveal the drug. The smell of bitter almonds indicates hydrocyanic acid. The educated Forensic Toxicologist will consider these indications before designing a series of tests to confirm the poison.

But what of those rare snake venoms and exotic biologic compounds that do not create an easily identifiable symptom?  Since there are thousands and thousands of elements that show up in an analysis, investigators normally don’t test for all of them.  For example, if the poison of an exotic stone fish was used to kill someone in the Utah desert, the crime lab there may miss testing for and discovering it.  But that poison did leave a signature.


The good, the bad and the ugly: a dedicated chemist.

Who makes a great forensic toxicologist? Those with the ability to follow detailed methodology and to interpret beyond that cherished systemic method in order to find the hidden answers. Yes, the forensic toxicologist will conduct hours of routine work, prepare mundane blood alcohol tests for drunk driving cases, test stomach contents and urine  for ‘date rape’ drugs and do all of this with the utmost professionalism. The daily routine will include hours standing in a lab dealing with messy and smelly organic materials. The forensic part of lab work will include learning grisly details about traumatizing, heinous crimes. It can be at times boring, intense, disgusting, lonely and tiring, but — if you are good at science, if you have patience and take pride in handling fine work and solving complicated puzzles, if you want to help solve crimes and bring justice to victims and their families, there is no better way to do good.

Your turn: Loved this piece in a series on future careers? Want to hear about how to get into another specialty we haven’t covered yet? Let us know in the comments. We’d like to hear from you.



One Comment

  • Vartika mohey says:

    Sir i am a forensic science graduate and i am interested in field work such as investigation. Also i have great interest in secret agencies working to couteract the terrorism.
    How can i get a job in this?
    Please show me all the available oppurtunities in india as well as in foreign countries.
    Thank you

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