Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Filtering by
Medicolegal forensic entomology is the study of insects to aid with legal investigations (Gemmellaro, 2017). Insect evidence can be used to provide information such as the post-mortem interval (PMI). Blow flies are especially useful as these insects are primary colonizers, quickly arriving at a corpse (Malainey & Anderson, 2020). The age of blow flies found at a scene is used to calculate the PMI. Blow fly age can be estimated using weather data as these insects are poikilothermic (Okpara, 2018). Morphological analysis also can be used to estimate age; however, it is more difficult with pupal samples as the pupae exterior does not change significantly as development progresses (Bala & Sharma, 2016). Gene regulation analysis can estimate the age of samples. MicroRNAs are short noncoding RNA that regulate gene expression (Cannell et al., 2008). Here, we aim to catalog miRNAs expressed during the development of three forensically relevant blow fly species preserved in several storage conditions. Results demonstrated that various miRNA sequences were differentially expressed across pupation. Expression of miR92b increased during mid pupation, aga-miR-92b expression increased during early pupation, and bantam, miR957, and dana-bantam-RA expression increased during late pupation. These results suggest that microRNA can be used to estimate the age of pupal samples as miRNA expression changes throughout pupation. Future work could develop a statistical model to accurately determine age using miRNA expression patterns.
In this experiment, the viability of gunshot residue (GSR) was examined. This was done through the very rarely researched intersection of forensic firearms analysis and forensic entomology. The question being resolved is if GSR can reliably be detected from secondary evidence transfer of GSR laden carrion onto flies and their larvae. While it is know that secondary and tertiary GSR evidence can be transferred by way of handshakes, no such research has been conducted on flies or their pupae. Findings indicated varying levels of detection of GSR on evidence. GSR could reliably be detected on fly bodies and their legs, but not on their pupae. This research is significant as it provides previously unknown information on this line of research and provides the groundwork for further research on this topic in the future.
When it comes to murder, there are many ways to go about it. From blunt force trauma to gunshot wounds to strangulation. However, there is one way that can be very effective and can even look accidental. This is through poisoning, more specifically, using plants as a weapon. Now there are many plant poisoning cases throughout the state of Arizona, most being accidental and dealing with animals, but there is also malicious intent behind some. The plants Nerium oleander L. (Oleander), Cycas revoluta Thunb. (Sago Palm), Ricinus communis L. (Castor Bean), Datura stramonium L. (Jimsonweed), and Cicuta virosa L. (Water Hemlock) are known to be poisonous and they are utilized by both murderers and those that wish to attempt suicide. These are also killers of many animals whether that be livestock or the family dog who got into something they should not have. The toxin in these plants breaks down on its own and over time can become untraceable. Most of them will also cause death if not treated within a few hours of ingestion, making them the perfect weapon to use to get away with murder.
