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Articles 1 - 9 of 9
Full-Text Articles in Forensic Science and Technology
Non-Destructive Dry Vacuum Recovery Of Dna From Fabric, Emily Sam-Zee-Moi
Non-Destructive Dry Vacuum Recovery Of Dna From Fabric, Emily Sam-Zee-Moi
Student Theses
Trace DNA has proved to be a reliable forensic tool when investigating crimes. Current methods of trace DNA recovery from fabric include cutting, swabbing, scraping, and tape lifting. A dry vacuum collection method originally developed for paper evidence is an alternative nondestructive option for DNA collection from fabric. This research evaluated the success of the dry vacuum technique on pieces of cotton fabric that had been briefly touched as well as the effectiveness of different moistening agents and filters. The samples were designed to simulate an assault with the suspect grabbing the clothing of their victim. Volunteers created samples by …
Evaluation Of The Age Of Evidence In Mock Biological Touch Evidence Samples, Emma P. Hirst
Evaluation Of The Age Of Evidence In Mock Biological Touch Evidence Samples, Emma P. Hirst
Master of Science in Forensic Science Directed Research Projects
As more sensitive DNA profiling techniques have been developed, questions about how and when the DNA was deposited have become a driving issue in forensic casework. Image flow cytometry (IFC) offers a way to estimate the time since deposition (TSD) of trace DNA samples based on individual cells' morphological and autofluorescence properties. Previous work has shown that a TSD can be determined from a single contributor in touch samples. To determine if TSD could be correctly estimated for mixtures containing a fresh deposit (less than a week old) and an older deposit, this project characterized a series of samples that …
Evaluating The Degradation Relationship Between Latent Print Impressions And Touch Dna Under Varying Environmental Conditions, Katrina M. Rupert B.S.
Evaluating The Degradation Relationship Between Latent Print Impressions And Touch Dna Under Varying Environmental Conditions, Katrina M. Rupert B.S.
Graduate Theses, Dissertations, and Problem Reports (ETD)
Latent prints have been processed as a source of touch DNA evidence in the hopes of attaining partial or even full DNA profiles. However, the relationship between the latent quality and the DNA quality has not yet been fully explored, resulting in gaps in understanding how the two are connected. A common source of touch DNA is from latent print evidence, which is typically processed and photographed at a scene, and subsequently processed for DNA in the laboratory. However, there is skepticism in the forensic community around touch DNA as laboratory procedures are often manipulated beyond standard operating procedures to …
Scientific Development Of An Integrated Workflow For Latent Print, Questioned Document, And Dna Processing Of Paper Evidence, Ashley Morgan
Scientific Development Of An Integrated Workflow For Latent Print, Questioned Document, And Dna Processing Of Paper Evidence, Ashley Morgan
Dissertations, Theses, and Capstone Projects
Touch paper evidence could be the source of probative human DNA but recovery is challenging and forensic laboratories instead prioritize processing by the Latent Print and Questioned Document disciplines. Recent advances in DNA collection methods and the increased sensitivity of STR typing kits have improved success rates for DNA testing of paper evidence; but prior to implementing DNA collection, laboratories have to decide in which order to examine paper for the different types of forensic evidence. This thesis developed and tested a multi-discipline workflow for processing paper evidence by DNA, Latent Prints and Questioned Documents experts. Preliminary sampling studies indicated …
Using A Non-Destructive Method To Estimate The Number Of Contributors And Predict Dna Yield In Touch Dna Mixtures, Christin Lee
Using A Non-Destructive Method To Estimate The Number Of Contributors And Predict Dna Yield In Touch Dna Mixtures, Christin Lee
Master of Science in Forensic Science Directed Research Projects
Touch DNA samples are low templates and often are mixtures, making them typically one of the most difficult types of evidence to interpret. Short tandem repeat analysis is a standard method to estimate the number of contributors and DNA yield for each contributor; however, there are some limitations. Applying a non-destructive pre-DNA analysis technique that provides information about the touch DNA may improve the casework process. Antibody probes to hormones such as testosterone and dihydrotestosterone (DHT), and proteins including cytokeratins (CK) inside epidermal cells, have been demonstrated to produce a personalized signature for human touch cell populations. Testosterone, DHT, and …
Evaluation Of A Novel Dna Collection Matrix Designed To Improve Recovery Of Touch Dna From Non-Porous Surfaces, Eric Ramirez
Evaluation Of A Novel Dna Collection Matrix Designed To Improve Recovery Of Touch Dna From Non-Porous Surfaces, Eric Ramirez
Student Theses
The collection of touch DNA from evidence has been a challenge in the field of Forensic Biology for decades. There are numerous collection protocols, substrates, and solutions that have been used to varying levels of success. Currently, no single method or substrate stands out as the single most effective collection protocol. The Gene Link Omni Matrix™ K105 solution is a novel collection method that can be sprayed onto the surface of non-porous evidence. The matrix dries into a film, capturing cells and cell-free DNA which can be scraped off and collected into a tube. During extraction, the matrix dissolves into …
An Exploration Of Protein And Dna Components In Fingerprint Residue, Ashley Borrego
An Exploration Of Protein And Dna Components In Fingerprint Residue, Ashley Borrego
Student Theses
The main focus of this project was to investigate the protein and DNA components in both sebaceous and eccrine fingerprints. This study investigated the relative content of DNA and proteins in eccrine fingerprints to sebaceous fingerprints. All volunteers were instructed to wash and dry their hands prior to depositing parallel thumbprints. Twenty volunteers were instructed to touch their face to produce sebaceous prints, and 5 volunteers were instructed to wear gloves over a heat source to produce sweaty or eccrine prints. Microscopy was used to score the cellular debris of the right fingerprint on a scale of 1-4 based on …
Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes
Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes
Student Theses
DNA testing on touched objects is a valuable tool in forensic investigations, but DNA is usually present in low amounts, causing poor STR typing results. For touch DNA evidence, there is a clear need for additional individualization, especially for highly probative samples. This could be achieved by testing genetically variable proteins. The goal of this project was to develop a DNA/protein co-extraction method to facilitate DNA and protein testing on the same evidence item. Existing DNA extraction methods were carefully adjusted to allow for downstream mass spectrometry analysis. Initial experiments on saliva and fingerprints placed on glass suggested that trypsin …
Touch Dna In A Complicated Alleged Child Abuse Case, Heather Miller Coyle
Touch Dna In A Complicated Alleged Child Abuse Case, Heather Miller Coyle
Forensic Science Publications
Touch DNA can be of use in establishing what may have occurred through reconstruction of events based on biological evidence transfer. However, interpretation of results and patterns must be approached with some caution as in the alleged child abuse case detailed here. This case was brought forward as a touch DNA and body fluid case where the male in question was a father reported to have forced a young child to perform oral sex on him. Her pajamas were collected and evaluated for presence of body fluids and associated DNA. The sleeves of the pajamas tested positive for amylase, a …