When you think of forensic science, your mind probably jumps to DNA swabs, fingerprints, or blood splatter analysis. But there is a lesser-known ally in uncovering crimes: fungi!
This growing field, called forensic mycology, uses the biology and ecology of fungi to answer important questions in criminal investigations like the time of death. Fungi are literally everywhere (on our skin, in the soil, in the air) and because they grow in very specific environments, they can leave behind some incredibly useful clues.
How fungi help forensic investigations
- Trace evidence
Fungal spores are microscopic and sticky. They cling to clothing, shoes, cars and even tools, and can act like trace evidence, helping link a person to a specific location.
- Estimating time since death
Some fungi begin growing on human remains just days after death. By looking at the type of fungus and how much it has grown, scientists can estimate how long a person has been dead. This is especially useful in cases where environmental data is insufficient or inconclusive.
According to an article, one real-life case involved a cadaver with Penicillium colonies on the skin. Investigators recreated the conditions in the lab, measured how fast the fungus grew, and estimated the body had been there for about 18 days, which matched the killer’s later confession.
- Determining time and place of deposition
Spores and fungal fruiting bodies found on or near a corpse can also reveal how long a body has been at a certain location or even if it was moved. Some fungi are seasonal and thrive only under specific conditions (such as temperature). If the body is covered with a type of fungi that normally grows in a different area or under different conditions, this can suggest that the body was moved.
In one unusual case, a twig under a plastic-wrapped body part had lichen growing on it, specifically Xanthoria parietina. When this lichen doesn’t get light or moisture, it changes color. Based on the discoloration, scientists figured out the twig had only been covered for about 5 days. This was an accurate estimate of when the body was moved to that certain area.
- Cause of death and poisoning
Some fungi are deadly such as the infamous death cap mushroom (Amanita phalloides) and Fly Agaric (Amanita Muscaria). Others cause hallucinations or strange behavior. Forensic mycologists can analyze stomach contents or leftover food to find out if someone was poisoned or intoxicated by mushrooms.
A recent example? The 2023 mushroom poisoning case in Australia, where a woman allegedly served a lunch that led to three deaths. Authorities suspect death cap mushrooms were used, and while the investigation is ongoing, experts believe forensic mycology is playing a crucial role in the case.
- Locating buried corpses
Some fungi, nicknamed “corpse-finders”( like certain Hebeloma species), grow especially well in soil that contains decomposing remains. Their presence might help search teams locate buried bodies, though this is still an emerging area of research.
Fungi are very helpful in crime investigation, but are there any challenges in this field?
First of all, there is the risk of misidentification. Especially in forensic settings, the samples might be degraded or mixed with other materials, which makes it harder to accurately identify the fungi species.
There are no widely accepted methods for collecting, preserving, and analyzing fungal trace evidence. Different labs may use different techniques, leading to inconsistencies in results and interpretations. Courts are cautious about admitting non-standardized science, which can reduce the impact of fungal evidence in legal proceedings.
If you would like to explore this field in more detail, here are two articles you can look into:
https://pubmed.ncbi.nlm.nih.gov/38986228/
https://impactfactor.org/PDF/IJPQA/12/IJPQA,Vol12,Issue2,Article15.pdf
fungitopia.org 