Forensic Science and Technology Commons^™

The Forensic Analysis Of Adult Temporary Tattoos, Paige Cooper

Student Theses

Adult temporary tattoos have become more popular, yet there is very little research on them, especially regarding their use in forensics. This poses a problem because forensic investigators may not be able to distinguish a temporary tattoo from a real tattoo, possibly hindering their investigation. In this study, various types of adult temporary tattoos were examined and analyzed in attempts to identify and distinguish them, both from each other and from permanent tattoos. Infrared spectroscopy, specifically attenuated total reflection (ATR), proved to be more useful than ultra-violet visible light spectroscopy in terms of analyzing the samples. The natural adult temporary …

The Accumulation Of Wear On Footwear Pattern Analysis, Sarah Pawloski

Themis: Research Journal of Justice Studies and Forensic Science

Wear is defined as the erosion of a shoe’s outsole or the loss of tread pattern, and it happens gradually over time with use. After a shoeprint is collected from a crime scene, it is questioned whether an individualization can be made if an exemplar is created after additional use of the shoe. The shoes of ten volunteers at San Jose State University were analyzed over a period of 40-45 days. Wear and Randomly Acquired Characteristics (RACs) were analyzed over time to determine if there were any observable changes or additions to the already present wear. It was hypothesized that …

Novice Ideas: Handwriting Comparisons Conducted By An Untrained Individual, Maia Lister

Themis: Research Journal of Justice Studies and Forensic Science

Forensic analysis of questioned documents includes chemical analyses of paper and ink as well as handwriting comparisons. Several elements affect handwriting analyses, including the presence of discriminatory factors that can individualize a handwriting sample and whether the handwriting has been disguised. Five handwriting samples were gathered from six individuals comprising of one reference, three natural unknowns, and one disguised sample per person. A novice conducted analyses on every collected sample and conducted comparisons of the reference sample to the unknown and disguised samples in an attempt to correctly source the unknown and disguised samples. The novice showed a high level …

Analysis Of Error Within Forensic Measurements And Photogrammetry Programs, Amy Douglas

Honors Theses

Digital images and photography have been considered commonplace in forensic science since the late 1990’s. Photogrammetry is a tool used in forensic science to measure objects within photographs that contain a scale or programs that are able to measure items in 3D images. Items at crime scenes often need to be measured and forensic scientists may not know what the best option is for their situation. This research will be conducted to show which type of measurement technique is most accurate, calculated against NIST traceable measurements, at various sizes of objects. The measurement techniques that will be tested are standard, …

Determination Of Vehicle Speed From Recorded Video Using Reverse Projection Photogrammetry And File Metadata, Brandon Epstein, Bryce Westlake

Faculty Publications

The prevalence of security and in‐car video has increased the number of motor vehicle accidents captured on digital video. However, inconsistencies in how to accurately determine time and distance for vehicle speed has led to examinations with varying results. A potential solution for calculating time intervals is to use frame timing contained within many digital video file's metadata, recorded with 0.000001 sec precision. This paper examines a fatal motor vehicle accident where frame timing information was used with distance measurements from reverse projection photogrammetry to calculate vehicle speed. A margin of error was then calculated based on the accuracy in …

The Potential Interference Of Body Products And Substrates To The Identification Of Ignitable Liquid Residues On Worn Clothing, Gina Guerrera, Erika Chen, Robert Powers, Brooke Weinger Kammrath

Forensic Science Publications

The question of whether deposits on clothing as well as their chemical composition are being mistaken for ignitable fluids is a concern for forensic analysts. Body products and oil secretions can have similar chemical profiles to ignitable liquid residues (ILRs) as a result of comparable chemical compounds that may be found in both sources. This study investigated whether substrates of unworn and worn clothing, with endogenous body secretions and body products could interfere with ILR analysis. Sample extraction was completed by passive headspace concentration with activated charcoal strips (ACS) and desorption with carbon disulfide followed by analysis with gas chromatography-mass …

Optimizing Methods For Separation Of Adhesive Tape From Fabrics And Obtaining Latent Prints From Adhesive And Non-Adhesive Sides, Elizabeth Vosburgh

Forensic Science Theses

Fingerprinting is a valued part of forensic science analysis. It has been around for decades, and has advanced with the passing of time. There have been numerous studies of the different ways analysts have encountered fingerprints in the field—but none on those deal with the removal of tape from fabric. To investigate this, eight fabric types (a cotton/polyester mix, spandex, denim, jeans, fleece, flannel, polyester, and vinyl), three commercially available tapes (duct tape, black electrical tape, and packaging tape), have been stuck together and separated with four different techniques (manual pulling apart, Un-Du commercial adhesive remover, liquid nitrogen, and a …

Assessing The Reliability Of Physical End Matching And Chemical Comparison Of Pressure Sensitive Tapes, Meghan Nicole Prusinowski

Graduate Theses, Dissertations, and Problem Reports

Pressure sensitive tapes are a common evidence type in a variety of forensic cases, including violent crimes, drug trafficking, and terrorism. Forensic laboratories are often requested to analyze tape samples for composition and potential source identification. Tape samples manufactured from different sources are often distinguishable when using a combination of sensitive analytical techniques. Nonetheless, the interpretation of the data remains challenging due to a lack of standard criteria and guidelines from which examiners can support their conclusions. As a result, there is a need to standardize the protocols of interpretation of physical and chemical comparisons of tape evidence.

The manufacture …