How Effective Are Poisons in Modern Times?

Murder & Crime

Apr 27

Poison has long been the murder weapon of choice for those who prefer silence over spectacle. Once synonymous with medieval plots and royal betrayals, poisons today face a new enemy…forensic science.

In the modern world, poison still kills, but rarely without consequence. From toxicology labs to autopsy tables, death leaves behind a chemical trail that even the cleverest killer can’t always cover.

How Poison Murders Are Detected Today

an example of a real toxicology report for horror writing reference

Thanks to significant advances in forensic toxicology, even trace amounts of poison can be detected long after a victim’s death. The following techniques are now standard in many investigations:

Blood and Urine Testing

Blood samples are analyzed within hours after death, often revealing opioid overdoses, sedatives, and other fast-acting toxins.
Urine offers a broader detection window, useful for substances that remain in the body longer.

Example: Opioid overdoses are usually confirmed through blood tests. Arsenic and lead show up in both blood and urine, but also build up in hair and nails.

Hair and Nail Analysis

Poisons like heavy metals leave behind lasting records. Hair strands, in particular, can capture exposure patterns over time, useful for chronic or repeated poisoning.

Example: Arsenic exposure creates visible Mees’ lines across nails, which alert to a systemic problem, and can be traced in the bands of hair growth.

Autopsy Observations

Medical examiners look for telltale physical signs:

Cyanide may turn skin pink or cause a faint almond smell.
Antifreeze (ethylene glycol) leaves behind kidney crystals.
Nerve agents can produce foaming at the mouth, twitching, and asphyxiation symptoms.

More advanced techniques like gas chromatography–mass spectrometry (GC-MS) can detect poisons at the molecular level, even in decomposed tissue.

Real-Life Poisoning Cases

Poison is rare, but when used, it often grabs national headlines due to its chilling nature. While there are many unique cases, here are a few that stand out:

The Eyedrop Case (2023)

In Texas, a woman was charged with killing someone using Systane eyedrops, which contain dangerous chemicals when ingested. The victim died of organ failure. Toxicology revealed the truth.

A black and white photo of Nannie Doss, a poisoner often used for horror inspiration — Nannie Doss being apprehended

Nannie Doss – The “Giggling Granny”

Between the 1920s and 1950s, Nannie poisoned multiple family members using arsenic. At the time, symptoms mimicked illness. Modern forensic patterns and multiple suspicious deaths led to her capture.

Alexander Litvinenko (2006)

A former Russian spy, Litvinenko was fatally poisoned with polonium-210, a radioactive substance. His lingering symptoms, hair loss, weight loss, and radiation sickness, ultimately unraveled a global conspiracy.

Does Poison Still Work in Fiction?

Yes, but only if you get it right. Most often, poisoning can come off over-the-top and even downright silly. Think of someone drinking from a cup and then flailing around. Not really believable, right?

Let’s look at some notable pop culture examples in which poisoning works well:

Breaking Bad – Ricin

Accuracy: High
Ricin has no antidote and its symptoms are consistent with those shown in the series, though some scenes shorten the real-world timeline.

A close up of Joffrey Baratheon's poisoned face from Game of Thrones — *Joffrey Baratheon from Game of Thrones*

Game of Thrones – Joffrey’s Death

Accuracy: Medium
His graphic, rapid demise after drinking wine was dramatic, but real poisons like cyanide or strychnine act more gradually and less explosively.

Gone Girl – Antifreeze

Accuracy: Reasonable
Antifreeze poisoning causes organ failure and takes hours to show symptoms. Its sweetness makes it difficult to detect without testing.

The Issue with Modern Poisoning

Today, using poison as a murder weapon comes with high stakes. While some toxins are still deadly, they rarely escape notice:

Medical advances offer treatments for many poisons, if caught in time.
Behavioral patterns often raise red flags before toxicology even begins.
Forensic techniques can uncover evidence even years later.

Using Poison in Your Next Thriller

If you’re incorporating poisoning into your horror or thriller, consider the aftershocks, not just the act:

Symptoms: Create dread with subtle signs, slurred speech, sudden fatigue, vomiting, or paranoia.
Cover-up attempts: Does your character destroy records? Bribe a pharmacist? Swap out wine bottles?
Consequence creep: Show how suspicion grows slowly, such as through a colleagues whisper, will change, or investigators digging deeper.

A slow, sinister death by poison can haunt long after the act. The real horror? It leaves clues behind.