Forensic palynology is the application of palynology, the study of pollen and spores, to legal issues. It uses the unique pollen and spore assemblages found in different geographic locations to associate people, places, and things. Analysis under microscopes can identify and compare pollen and spore samples to determine if they originated from the same source. Two case studies are described where forensic palynological evidence helped identify a crime scene and associate a suspect with a crime scene through pollen evidence. While not widely used in the US, it has been an important forensic technique used in other countries.

1. Forensic Palynology
Presentation by Francesca Beer

2. “( r ) Pollen – The wind likewise transports pollen
dust, whose constant presence is noted on
garments and on the body during the summer
season. It is found in the ears as well as in the
nostrils where the pollen produces the
inflammation called hay fever.”
“( u ) Mushroom Spores – …On the other hand,
spores collected in dust are often quite
characteristic and permit us up to a certain
degree to determine what the bearer has been
recently doing, such as walking in a wood,
collecting mushrooms, etc.”
~Edmond Locard, 1930
“The Analysis of Dust Traces, Part II”
The American Journal of Police Science
Volume 1, Issue 4

3. What is Forensic Palynology?
• Palynology is the study of fossil and modern
‘palynomorphs’
• A palynomorph is defined as a particle made of
organic material that measures between 5 and
500 micrometers and is found in sedimentary
deposits
• The most commonly studied palynomorphs are
pollen and spores, leading many to falsely believe
that palynology is in fact the study of pollen and
spores.

4. What is Forensic Palynology?
• Forensic Palynology is the application of
palynology to legal issues and the law.
• Forensic palynology primarily analyzes spores
and pollen as a form of trace evidence.
• Although things like fossilized organic structures,
arthropod organs, and certain worms and
protists are considered palynomorphs, Forensic
Palynology is more concerned with spores,
pollen, and other powered minerals and how
they can be used in a legal context.

5. What can Forensic Palynology do?
• Forensic Palynology can:
– “Relate a suspect to a crime or discovery scene
– Relate an item left at a crime or discovery scene
to a suspect or victim
– Relate an item found on the suspect or victim to a
crime or discovery scene
– Relate an item at the discovery scene to the crime
scene
– Prove or disprove an alibis

6. What can Forensic Palynology do?
– Determine the travel history of items
– Provide information of the environment an item
has come from or was in
– Aid police in investigation
– Determine if a body was moved, pre, post, or peri
mortem
– Determine approximately how old human remains
are”
– …and much more
– Mildenhall, D., P. Wiltshire, and V. Bryant. "Forensic Palynology: Why Do It and How It
Works." Forensic Science International 163.3 (2006): 163-72. Print.

7. How does Forensic Palynology Work?
• Forensic Palynology is based upon the
Locard’s Exchange Principle, that is, that
“every contact leaves a trace.”
• It uses the pollen and spores of native plants
of certain geographical locations to place
someone or something somewhere
– Examples are: placing a suspect at a crime scene,
supporting or disproving an alibis, placing an item at a
crime scene, and much more.

8. How does Forensic Palynology Work?
• Forensic palynology primarily uses microscopy to
compare, identify, and analyze samples of pollen
and spores.
• The morphology of pollen and spores is incredibly
diverse, allowing identification to a specific
taxon, normally accurate to genus or even
species, by visual comparison.
• A pollen assemblage is the number of identified
pollen and spores found in a sample.

9. How does Forensic Palynology Work?
Morphology of Pollen and Spores
• The diversity of morphology of the pollen and
spores is manifested in their cell wall structures.
Characteristics include:
– Size
– Shape
– Wall Pattern
– Wall Thickness
– Apertures
• The diversity in these characteristics allows
relatively precise identification.

10. Scanning Electron Microscope (SEM) image of
miscellaneous pollen particles
http://upload.wikimedia.org/wikipedia/commons/a/a4/Misc_pollen.jpg

11. How does Forensic Palynology Work?
• While Scanning Electron Microscopes are preferred
for their accuracy and clarity at such small scales,
most palynologists can only use light microscopes for
identification due to lack of funding or access to an
SEM.
• When identifying a pollen grain or spore, a
photograph or known sample is required.
• There are various databases of pollen grains and
spores, such as the Global Pollen Database, the
European Pollen Database, etc.
• Occasionally, palynologists will request samples of
similar morphology from herbaria or fungaria for
comparison.

12. Daisy Pollen under Light Microscope and SEM
Light Microscope Scanning Electron Microscope
Light: http://www.abc.net.au/reslib/201110/r841964_7864873.jpg
SEM: http://www.abc.net.au/reslib/201110/r842009_7866030.JPG

13. How does Forensic Palynology Work?
• Palynologists can compare two soil samples and,
depending on the percent composition of the
identified spores and pollen in the soil, can
determine if the samples originated from the
same location.
• Palynologists will never find two identical
samples, however, using the similarity of the
percent composition of the pollen and spores in
the soil, they will be able to identify which
samples are significantly similar or significantly
different, that is, if they came from the same
location or not.

14. Why use Forensic Palynology?
• Pollen and spores are very durable – able to last
millions of years in the correct environment and
are resistant to chemical and mechanical
damage.
• They are small and are easily trapped in clothes
and fibers, as well as soil, skin, and other mucous
membranes.
• They are abundant in almost all environments.
• They are also rather easily transferable between
places, people, things, etc.
• Because of this, they are a reliable form of trace
evidence.

15. Why use Forensic Palynology?
• Since pollen and spores are so durable, they can
leave a vegetative history in the soil. This
vegetative history is unique to the area, which is
why soil samples are able to be used to identify
locations
• Similarly, their endurance allows them to stick to
clothes, skin, etc, for quite a long time without
being degraded or destroyed, allowing them to
be used as evidence even years after a crime.

16. Palynology as a Forensic Discipline
• Forensic Palynology is not practiced often in the
United States, but is widely accepted and used in
New Zealand, Australia, and the United Kingdom.
• As a tool of forensic science, palynology is quite
labor intensive, expensive, and requires a certain,
rare level of expertise.
• Because of this, as well as the ignorance of
palynology’s potential as a forensic discipline,
many other countries, especially the United
States, have not invested much in it.

17. Forensic Palynology Cases
• Two males entered the house of a woman
and her live-in boyfriend through the back
door. The woman was home alone, asleep,
with the back door unlocked for her
boyfriend to get in the house when he
returned. The woman awoke to sounds in the
house and discovered the intruders, who
quickly fled. One of the intruders left his
jacket at the house, and later returned to
retrieve the jacket. In a rush, he carelessly
brushed against a ‘Hypericum’ plant that was
blooming by the back door.

18. Forensic Palynology Cases
• A suspect was arrested and, after analysis of his
clothes, the palynologists found that the concentration
of Hypericum pollen was unable to have been swept
onto the clothing by wind dispersal and they had to
have been in direct contact with the bush. They also
found the pollen from the bush to be identical to the
pollen sampled from the Hypericum bush in question.
• The palynological evidence alone did not convict the
suspect, but along with other evidence obtained, as
well as positive identification of the suspect by the
victim, the suspect was charged with burglary.
• Mildenhall, D. "Hypericum Pollen Determines the Presence of Burglars at the Scene of
a Crime: An Example of Forensic Palynology." Forensic Science International 163.3
(2006): 231-35. Print.

19. Forensic Palynology Cases
• A girl was walking the streets of New Zealand
when she was grabbed, threatened, and
raped. The victim identified a scene, but
there were questions as to its reliability.
During the investigation of the area, they
found, in great number, ‘Coprosma’ shrubs, a
relatively common shrub found in the area.
They sampled pollen from the shrubs and
found a very unique characteristic: The pollen
sampled from the scene had fungus growing
on it, small branches of the fungus even
growing into the pores of the grains.

20. Forensic Palynology Cases
• They examined the victim’s clothes and found
Coprosma pollen, and upon further examination
they found that the pollen of her clothes
matched morphologically and had the same
fungus growing on the grains, similarly the
branches of the fungus growing into the pores.
• It was concluded that the scene must have been
the scene of the crime due to this.
• Mildenhall, D. "An Unusual Appearance of a Common Pollen Type
Indicates the Scene of the Crime." Forensic Science
International 163.3 (2006): 236-40. Print.

21. References
• Locard, Edmond, and D. J. Larson. "The Analysis of Dust Traces. Part
II." The American Journal of Police Science 1.4 (1930): 401-18.
Print.
• Mildenhall, D. "An Unusual Appearance of a Common Pollen Type
Indicates the Scene of the Crime." Forensic Science
International 163.3 (2006): 236-40. Print.
• Mildenhall, D. "Hypericum Pollen Determines the Presence of
Burglars at the Scene of a Crime: An Example of Forensic
Palynology." Forensic Science International 163.3 (2006): 231-
35. Print.
• Mildenhall, D., P. Wiltshire, and V. Bryant. "Forensic Palynology:
Why Do It and How It Works." Forensic Science
International 163.3 (2006): 163-72. Print.
• Walsh, Kevan A.J., and Mark Horrocks. "Palynology: Its Position in
the Field of Forensic Science." Journal of Forensic Sciences 53.5
(2008): 1053-060. Print.