No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The use of animal-dispersed seeds and fruits in forensic botany
Abstract
A specific case of the forensic use of animal-dispersed propagules is presented, and it is suggested that this type of evidence deserves wider utilization by the law enforcement community. Animal dispersed seeds and fruits are ubiquitous, often cling tenaciously to clothes or other materials worn or used by suspects, and are small and frequently go unnoticed. Furthermore, their identification is relatively inexpensive and technically straightforward, and their presentation as evidence is visually and intuitively obvious, making it ideal for the courtroom. It is also suggested that forensic botany is an excellent topic to use as a case study in college botany or biology classes because of its inherent interest and integrative nature. In order to facilitate such usage, a brief review of some aspects of forensic botany is presented including references to pertinent literature.
... The use of plant materials in modern homicide investigations was brought into focus by the 1935 trial of Bruno Richard Hauptmann for the kidnapping and murder of the 20-month-old son of Charles A. Lindberg, the famous American aviator (1). In recent years, evidence from plant materials and identification of plant species has been used in a number of ways in homicide investigations (2,3) and in other criminal cases and lawsuits (4)(5)(6)(7). We have developed procedures for using plant cell identification techniques specifically to characterize vomit or gastric contents with respect to their composition and relating that to last known meals of homicide victims (8). ...
Fecal matter analyses were applied to two cases: a homicide and a robbery. Scrapings of fecal matter removed from samples of clothing obtained from a homicide suspect were examined for their plant cell and cell fragment content and compared with fecal matter from a rape-homicide victim and scrapings from her clothing. Scrapings were hydrated and examined microscopically. Types of food plants were identified from the observed cells by comparison with known food plants. A similar analysis was conducted on the clothing of a robbery suspect and compared with fecal material left at the crime scene. The results showed that, respectively in the two cases, the reference samples were remarkably similar, if not identical, to those from the suspects' clothing.
Plants are a good source of biological forensic evidence; this is due to their ubiquity, their ability to collect reference material, and their sensitivity to environmental changes. However, in many countries, botanical evidence is recognised as being scientifically. Botanical evidence is not mostly used for perpertration, instead it tends to serve as circumstantial evidence. Plant materials constitute the basis, among others, for linking a suspect or object to a crime scene or a victim, confirming or not confirming an alibi, determining the post-mortem interval, and determining the origin of food/object. Forensic botany entails field work, knowledge of plants, understanding ecosystem processes, and a basis understaning of geoscience. In this study, experiments with mammal cadavers were conducted to determine the occurence of an event. The simplest criterion characterising botanical evidence is its size. Therefore, macroremains include whole plants or their larger fragments (e.g. tree bark, leaves, seeds, prickles, and thorns), whereas microscopic evidence includes palynomorphs (spores and pollen grains), diatoms, and tissues. Botanical methods allow for an analysis to be repeated multiple times and the test material is easy to collect in the field. Forensic botany can be supplemented with molecular analyses, which, although specific and sensitive, still require validation.
Um cadáver humano com sinais de violência física foi retirado das águas do Lago Guaíba, próximo à zona portuária do cais central em Porto Alegre. A vítima trouxe, aderidos às vestes, vestígios de vegetais terrestres, entre outros achados de interesse criminalístico. O exame mais apurado do material vegetal revelou tratar-se de um tipo de “pega-pega” e outra espécie de “carrapicho”, ambos aderidos na face externa do terço superior das calças. Tais estruturas eram pequenos frutos secos, que possuem cerdas ou ganchos utilizados para adesão aos pelos de animais, ou, eventualmente, ao tecido das roupas humanas. Algumas plantas apresentam tal estratégia para disseminação de suas sementes, chamada de dispersão epizoocórica. Conhecendo tal mecanismo de propagação das plantas que geram diásporos, o endemismo e tendo dados de ocorrência das espécies identificadas, poderíamos inferir onde teria sido o local original de violência contra a vítima, que foi localizada boiando no canal de navegação do Guaíba. Elaborado a partir de um caso real, conhecimento taxonômico e pesquisa bibliográfica, o presente trabalho busca dar subsídios para o reconhecimento de diferentes espécies de plantas produtoras de diásporos no âmbito forense, relacionando a identificação da espécie à zona de distribuição e de ocorrência. O caso estudado destaca a epizoocoria no contexto da botânica forense, além disso, salienta a imprescindível interação de peritos criminais com botânicos taxonomistas na correta identificação dos vestígios, para que tais conhecimentos possam servir como mais uma ferramenta na elucidação de crimes.
The kidnapping and death of American aviator hero Charles Lindbergh's young son in 1932 was labeled the 'Crime of the Century.' A hand-made wooden ladder left at the scene provided some of the most critical evidence connecting Bruno Richard Hauptmann to the crime. The information was supplied by Arthur Koehler, wood technologist for the U.S. Forest Service who, with remarkable tenacity and by meticulously detailed studies, was able to provide three lines of plant anatomical evidence crucial to Hauptmann's conviction and subsequent execution. Koehler traced part of the ladder's wood from its mill source to a lumberyard near the kidnapper's home through faint machine planing marks even before the suspect was known. After Hauptmann's arrest, Koehler demonstrated by wood anatomical comparisons that one of the side rails of the ladder previously had been part of a floorboard in Hauptmann's attic. Finally, he established that Hauptmann's hand plane had been used to dress the edges of several ladder parts. Koehler's testimony in this important trial was a turning point in the acceptance of botanical evidence as expert scientific evidence in the courts. In spite of the direct connection to Hauptmann indicated by the wood anatomical structure and markings from the ladder, Hauptmann maintained his innocence until the end. The case has been reexamined in recent years by several groups and individuals. Although some believe in Hauptmann's innocence, the wood anatomical evidence remains unchallenged in incontrovertibly linking Hauptmann to the crime.
The mass of material plugging the B2 elbow was 4.1 mm in diameter and 0.6 mm thick. It consisted of both light and dark colored organic material mixed with stellate trichomes and the pollen of several plants found near where the aircraft wreckage was stored. The mass was colonized by fungi such as Alternaria and Cladosporium. The organic matrix consisted of two dissimilar materials: A dark 'gum-like' material and a lighter, golden- colored 'nectar' and was subjected to FT-infrared (FTIR) spectroscopic analyses. Both reflectance and transmission FTIR techniques were used in the analyses, but the best results were obtained from transmission FTIR. This required that opaque substances such as the organic matrix be prepared as thin films. Several materials were collected from near the storage site as reference materials and these were also analyzed by FTIR spectroscopy. The reference materials included leaf and sap from Sphaeralcea coccinea and Grindelia squarrosa growing around the storage site. Commercial honey, cleaning solvents, and other organic fluids used in the aviation industry were also analyzed as well as gummy deposits found in equipment unrelated to the aircraft wreckage but stored near the aircraft parts. Mixed FTIR spectra were obtained from the organic matrix found in the B2 elbow, but showed a significant carbohydrate component. Comparison of these spectra to the reference materials clearly showed that the organic matrix was composed of macerated Sphaeralcea leaves mixed with a honey-like nectar.
The crash of a private plane near Ruidoso, New Mexico in 1989 resulted in an investigation of a small mass of biological material isolated from a tubular component of the fuel assembly. Part of the biological material consisted of a small pellet of pollen. The pollen grains were glistening, bright yellow in color, and surrounded by a moist hyaline substance that formed thin strands connecting the individual grains. If the grains had accumulated over time, some would have been subjected to an air temperature of about 500°F (190°C) for the operational life of the fuel component. If they were present before the crash, they also would have been exposed to a post-crash fire that distorted aluminum parts and melted resin/fiberglass construction material. Experiments with fresh pollen demonstrated that the grains darkened significantly with moderate heating for short periods, and that the connecting strands disappeared. The conclusion, consistent with other biological, chemical, and soil evidence, was that the biological mass was a post-crash accumulation unrelated to the accident.