Cases where forensic botany has been used in criminal investigations
Question: Give an outline of cases where forensic botany has been successfully used in crime investigations.
Forensic botany is the use of plant evidence in court. Forensic botany is subdivided into several botanical subspecialties, including plant anatomy the study of cellular features, plant systematics taxonomy and species identification, palynology the study of pollen, plant ecology plant succession patterns, and limnology the study of freshwater ecology. All these can be used as trace evidence to help reconstruct a crime scene or help in recreating previous events (Heather, 2004).
Forensic botany encompasses many sub disciplines, including plant anatomy, plant ecology, plant systematics, plant molecular biology, palynology, and limnology. Although the field of forensic botany has been recognized since the mid-1900’s, the use of trace plant material as physical evidence in criminal casework is still novel (Lee et al, 2001). Forensic botany is still an under-utilized resource in forensic casework, although it has been used on occasion. It is an area of specialty science that could include traditional botanical classification of species, DNA, or materials evidence (trace and transfer evidence), crime mapping or geo-sourcing, all dependent on the specific case application under consideration (Heather, 2004).
The major plant groups identified as pollen sources include flowering plants, conifers, and ferns. Ferns technically produce spores instead of pollen but are included in pollen types. Pollen is microscopic and not visually obvious trace evidence during crime scene collection but is retained on clothing, embedded in carpets and pervasive in soil. Pollen grain morphology can be used to identify a plant genus and often the species. Crime scenes that are restricted to a few square meters, such as a rape scene or the entry point of a burglary, are good choices for pollen evidence. Localized areas have a specific pollen distribution pattern representing the combination of plant species found in the surrounding vegetation. Common pollen types from plants that use wind for distribution will be less useful than pollen from uncommon, poorly distributed species. Insect distributed pollen is typically deposited within a few feet of the source plant. Pollen analysis consists of species identification and an estimation of the percentage that each plant species represents in an evidentiary sample. A similar pollen composition from shoeprints and from the shoes that made the prints indicates a strong match correlation. Pollen evidence collected from a burglary entrance and a suspect’s shoes, for example, could provide a linkage in a case (Brown et al, 2002).
There are a number of cases were botany was used to solve problems to investigations and findings. The first case that I will be looking at which was successful using botany was the Bosnia case in 1997 to 2002 when a team of forensic personnel worked with the United Nations International Criminal Tribune to exhume war graves in North East Bosnia. Reports stated that in 1995 hundreds of Serbians were massacred and buried in 7 large graves. Other reports stated that 3 months later, most bodies were exhumed and reburied in many secondary graves to appear to be local burials. 240 pollen samples were collected from primary and secondary sites to determine if the bodies in secondary graves were original or if they had been exhumed and reburied from the 7 mass graves. The pollen evidence confirmed that the bodies had been killed and buried in one location and then exhumed and moved to a new location (Bryant, ).
Another case is the Magdeburg, Germany case. In 1994 a mass grave was found with 32 male skeletons, many of them shot in the back of the head. The region was under German control until Soviet troops took over in summer of 1945. Questions were asked but there was no enough evidence to answer them. Were they Russian prisoners killed by the German Gestapo? Or were they Russians killed by the KGB in 1953 after a revolt in that area of East Germany? They had no answer to all the questions. Pollen material was collected from the nasal passages of 21 skulls and examined. The dominant pollen types were Plantago, Tilia, Secale, and traces of late summer flower pollinators. The pollen tests results proved that the Russians killed the 32 males in 1953. Thus palynology a very important branch of botany was used to solve and come to conclusion of certain cases that were unanswered (Heather, 2004).
Due to the smallness in size of pollen it is more efficient to use even in plant identification and also it doesn’t decay. Another case were palynology was used is the Texas Murder in 1995. Murdered victim’ body was found dumped on a dirty road near a major highway in West Texas near Abilene. Victim had been stabbed 21 times, hands had been cut off which means no fingerprints could be used to identify the victim and most clothing was missing. Victim was killed someplace else, and the victim was Hispanic. Efforts were made to solve the case but the case was closed months after and was considered as a cold case because the investigators had given up on their search. All efforts to identify the victim failed to discover who he was and why he was killed. In 1996, the crime scene investigator from this case attended a forensic lecture were he learned about forensic palynology, he believed it is worth trying. Victim’s clothing (shirt, socks, and shoes) had been removed from the body and placed in sealed paper bags after the autopsy, bags had remained closed and stored in evidence room since the murder. Team returned to the crime scene to collect control samples to test pollen print against the pollen found on the victim’s clothing. Forensic pollen studies were conducted on each item of the victim’s clothing. Marijuana pollen (Cannabis) was found in large amounts on victim’s shirt and socks; the amount of marijuana pollen was much higher than the amounts found in the “pollen print samples” from the region of West Texas where the body was found. Socks and dirt on shoes contained alder (Alnus) and buffalo berry pollen grains (Shepherdia argentea) which none of the pollen plant grows in the area, neither of those pollen types was found in the control samples from the crime scene which brought the investigator to a conclusion that the victim came from some region north of the crime scene. The location of the alder and buffalo berry pollen grains changed the direction of identifying the victim but the victim was never identified but they concluded that the victim was killed in Kansas and later dumped in Texas (Bryant, 2001).
However, a man was arrested at the Texas-Mexico border with a truck which was full of boxes containing variety of ancient Native American artifacts. The artifacts included ancient sandals, baskets, spears, nets, & pottery. The artifacts were sent to Texas to determine the origin of the artifacts. Dirt was collected and woven artifacts were vacuumed for pollen. The pollen data from the artifacts closely matched with the control samples from Mexico. The pollen in the control samples are the pollen which were collected from the man’s ranch. So the conclusion that was made artifacts were of Mexican in origin the person was importing illegal artifacts (Bryant, 2001).
Another case which was successful, used algae to link a weapon used in a homicide case to a nearby freshwater pond. The case is of a young wife who was murdered by her husband in the living room of their home. The investigators found that her head had been struck by a blunt object, and there were plant material and abrasions which were found on her body and clothes. The husband had initially insisted that his wife was found on the sofa, but when the plant material matched to other vegetation in the driveway, he changed his story. Further, investigations led to the identification of a brick in the pond behind the house with hair and tissue from the victim. Thus forensic botany hopes in by analyzing the algae and matching hair and tissues to the deceased on the brick linking the weapon and the crime scene. To link the husband to the weapon and the crime scene, the investigators looked at the on the T-shirt that he had been wearing when he said he found his wife’s body. Botanists and forensic scientists carried out microscopic analyses of the algae species on the cloth and identified that the algal species on the shirt as being the same as those found in the pond. Therefore, they successfully establish the link between the husband and the weapon (Heather, 2004).
There is also another case of the southern England were botany (limnology) was also used to solve unanswered questions of an investigation. In July 1991, two young boys were attacked by a group of teenagers while they were fishing at a suburb pond. The boys were threatened with a knife and were bound with a tape while the teenagers group beat them up with a baseball bat. After beating the boys up the group of teenagers dragged the boys into the pond to drown. One of the boys managed to escape out of the hands of these cowards and decided to rescue his friend by reporting the case. An investigation was carried out and led to the apprehension of three suspects. While the forensic botanist was trying to link the suspects to the crime scene, sediment encrusted sneakers were recovered from both the suspects and victims and were analyzed for aquatic micro-organisms. Many species of diatoms were observed to analyze if they match with that from the reference sample. The percentage of the matching algae diatoms managed to link the suspects to the crime scene (Szibor, 1998).
In conclusion, there are a number of cases were botanical evidence was used and the cases were successful using the different sub branches of botany such as palynology, limnology, plant morphology and etc. Botanical evidence cannot work alone also in some cases to be able to pin down a suspect or link to a scene of incidents. There is also the need to aid with, like DNA and fingerprints. There is also another case were the wood used to make a ladder was examined and a weapon was linked to the wood manufacturer. So there are so many cases that were successful using botanical evidence.
REFFERENCES
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3. Heather M.C (2004). Forensic Botany: Principles and application to criminal casework. CRC press.
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5. Szibor R, Schubert C, Schoning R, Krause D, Wendt U.(1998). Pollen analysis reveals murder season. Nature. Chapter 395 page 449-50.
