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Nature-identical synthetic vanillin

Produced from C3 lignin which has a more negative signature δ13C = -27‰.

C3 plant based vanilin 

Can be mixed with ^13C-enriched vanilin. Detection via position-specific δ13C or global δ2H analysis

Falsification with ^2H labeled vanilin.

Detection via position specific δ2H analysis. Or additional measures like δ18O

Stable Isotope Analysis (SIA)

Is a valuable forensic tool for identifying unidentified human remains, particularly in missing persons cases. It works by measuring the natural variations of stable isotopes—such as hydrogen (²H), oxygen (¹⁸O), carbon (¹³C), nitrogen (¹⁵N). Since the abundance of a spefic stable isotopes varies between geograpical regions because environment condition which include factors like temperature, humidity, precipitation, altitude and plant diversity.

Hydrogen (²H/¹H, δ²H) and Oxygen (¹⁸O/¹⁶O, δ¹⁸O)

Reflect the isotopic composition of drinking water, which varies geographically due to precipitation, altitude, and climate. Useful for mapping residence or travel history via water isoscapes.

Carbon (¹³C/¹²C, δ¹³C

Indicates types of plants consumed (C₃ vs. C₄ photosynthetic pathways) and helps distinguish between marine and terrestrial diets.

Nitrogen (¹⁵N/¹⁴N, δ¹⁵N)

Reveals an individual's trophic level—higher values suggest more meat or marine food consumption, and may reflect health or physiological stress.

Plant ecology

Knowledge on plant ecology can be key in forensic investigations. For example Plant interaction with objects or living things can induce plant damage which can provide forensic evidence- e.g. a car driving over grass, rest of weeds on shoes. Or If a body or object is buried, root meristems could get damaged, and this could help track the time this event happened.

Palynology

Is the study of pollen grain and spores. In angiosperms, pollination is the transfer of pollen from anthers to stigma and it can occur by wind, water, animals or self-pollination. Can be used to link individuals or items to specific locations and seasons. Pollination by birds and insects are relatively large, viscous and heavy and falls much more rapidly, but also near the mother plant. Which can be useful in forensic evidence. Pollination by wind tends to produce small, unnoticeable flowers that lack nectar or scent and release large amounts of pollen. And 95%  of pollen from wind pollinated plants fall 25m-2km from the mother plant, so their presence at the crime scene does not mean that the mother plant grows nearby. 

Limnology

Study of freshwater bodies (focuses on the presence of diatoms in crime scene samples and on victims).

Plant anatomy

Different parts of the plants can be used to provide forensic evidence. Identification of plants helps to determine a sample’s geographic origin, provide links between crime scene and individuals, test alibis, ascertain the possession or trade in forbidden or endangered species, and more. It can be based on morphological features such as leaves, stems and flowers. Can also be used to Determine if an illegal antique is made from protected hardwood. Each tree species has a distinct wood grain, cellular structure, and sometimes scent. 

Dendrochronology

Is the study of tree growth rings. The width of the rings provides evidence of the environmental conditions at the time – thick rings reflect good growth conditions. Dendrochronology does not involve counting tree rings but comparing ring patterns between trees and wood products. Provides evidence of the age of an object and also the date a tree has fallen. Useful when a tree is found growing through a skeletonized body or within a grave plot.  

Plant secondary metabolites

Many plants produce toxic or psychoactive compounds. Which can be used to identify poisoning or drug-related crimes. Analysis of stomach contents, vomit, or residues can reveal ingestion of poisons (e.g., ricin from castor beans) or drugs (e.g., morphine from poppies). 

Molecular methods

Methods like DNA barcoding using regions such as matK, rbcL, and ITS allow accurate plant identification when physical traits are unclear, though they can be time-consuming and expensive

Bryology

Bryophytes like Mosses, Liverworts and Hornworts can be used to estimate postmortem interval (PMI) and linking evidence to moist environments. These small, non-vascular plants grow in damp, shaded areas and can adhere to clothing or shoes. Their growth stages help estimate how long an object or body has been at a scene. Moss growth in shoe treads indicating a body was left in one place for weeks or months.