2021 American Academy of Forensic Science 73rd Annual Scientific Meeting
February 15th–19th: Virtual
Student: Alan Lee
Poster on: Estimating Muzzle-to-Target Distance from the Physical Characteristics of a Bullet Hole
Determining the muzzle-to-target distance of a firearm discharge is an integral part in crime scene reconstruction. When combined with the bullet’s trajectory and impact angle, the shooter’s location can be approximated, which can support or refute eyewitness accounts and suspect statements. This study sought to develop a method using physical damage patterns of a bullet hole to determine the muzzle-to-target distance. Test fires were conducted with a .22 caliber rifle over a range of muzzle-to-target distances on plywood and Medium Density Fiberboard (MDF) panels. The results show that as muzzle-to-target distance increases, bullet hole depth decreases. This trend was steeper in the plywood substrates than MDF. Using the data from the test fires, a mathematical model was able to predict depth given the substrate material, muzzle-to-target distance, and bullet speed. A visual model that relates the depth of the bullet hole to the muzzle-to-target distance can extrapolate the distance, as long as substrate, firearm, and cartridge information are obtained from the scene.
2021 American Academy of Forensic Science 73rd Annual Scientific Meeting
February 15th–19th: Virtual
Student: Xiao Chen
Talk on: Evaluating a Test for Shedding Propensity Using Tape Lifts from Different Skin Locations
The shedding propensity of a person can assist data interpretation in casework when assessing the possibility of passive transfer for DNA analysis results. Currently, there are different methods to determine shedding propensity, all based on evaluating palmar skin (finger) deposits, but there is no standardized method, especially for an uncooperative suspect. This project tested the feasibility of testing sebaceous skin for shedding propensity through collecting skin surface tape lifts from eight different locations (washed and unwashed fingers from both hands, toe, and sebaceous skin areas like arm, ear, and nape). DNA yields were highest for the neck area below the ears followed by nape and unwashed fingers. Donors did not easily fall into different shedding propensity categories. Individual DNA values showed a continuous distribution from low to high concentrations. Correlations between sebaceous and palmar skin DNA yields were not strong enough to support substituting finger surface lifts with sebaceous skin locations.
Presented at the 2020 Virtual NEAFS Meeting
October 14th–17th
Student: Genevieve Trapani
Study: Determination of Shedding Propensity Based on STR Results
Trace DNA evidence can be deposited at a crime scene due to either active or passive transfer. Based on previous studies, the probability of depositing a detectable amount of DNA through touch and the odds for passive transfer depend on the individual’s shedding propensity, and determining the shedding propensity of a person of interest can aid in trace DNA casework interpretation. As expected, STR results for unwashed hands showed a higher percentage of DNA mixtures. Accordingly, shedding propensity was determined based on STR profile quality and number of the expected alleles present for washed hands only. Out of the 28 volunteers, three individuals were consistently low shedders, the majority of 21 individuals were intermediate shedders, and only four individuals were high shedders. This distribution is similar to data from other studies.
2020 American Academy of Forensic Science 72nd Annual Scientific Meeting in Anaheim, CA
February 17th–22nd: Anaheim Convention Center
Student: Natalia Platosz
Talk on: Identification and Quantification of Classic, Prescription, and Synthetic Opioids in Hair by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS)
Drug testing tools to monitor opioid use and abuse habits in both the living and postmortem are necessary to understand the opioid use pattern, identify risk groups, and cause of death. Hair is becoming an alternative matrix of increasing interest in forensic toxicology to investigate drug use and abuse patterns due to its long window of detection. This project tested 25mg of hair. The Limit Of Quantification (LOQ) was established to be 1pg/mg (3-methyl-fentanyl, 4-anpp, 4-methoxy-butyryl-fentanyl, acetyl fentanyl, acrylfentanyl, alfentanil, butyryl fentanyl, carfentanil, EDDP, fentanyl, furanyl-fentanyl, isobutyryl fentanyl, MT-45, para-fluorobutyryl fentanyl, sufentanil, U-47700, and valeryl fentanyl), 10pg/mg (6-acetylmorphine, hydrocodone, methadone, morphine, norfentanyl, oxycodone, oxymorphone, and tramadol), or 100pg/mg (codeine and hydromorphone). The method was fully validated following the Scientific Working Group for Forensic Toxicology guidelines. The parameters evaluated were linearity, limit of detection and LOQ, imprecision, accuracy, carryover, matrix effects, extraction efficiency, process efficiency, interferences, and autosampler stability.
2020 American Academy of Forensic Science 72nd Annual Scientific Meeting in Anaheim, CA
February 17th–22nd: Anaheim Convention Center
Student: Julian Beach
Talk on: The Relationship Between Terminal Velocity and Glass Fracture via .177 Caliber Steel BBs
Drug testing tools to monitor opioid use and abuse habits in both the living and postmortem are necessary to understand the opioid use pattern, identify risk groups, and cause of death. Hair is becoming an alternative matrix of increasing interest in forensic toxicology to investigate drug use and abuse patterns due to its long window of detection. This project tested 25mg of hair. The Limit Of Quantification (LOQ) was established to be 1pg/mg (3-methyl-fentanyl, 4-anpp, 4-methoxy-butyryl-fentanyl, acetyl fentanyl, acrylfentanyl, alfentanil, butyryl fentanyl, carfentanil, EDDP, fentanyl, furanyl-fentanyl, isobutyryl fentanyl, MT-45, para-fluorobutyryl fentanyl, sufentanil, U-47700, and valeryl fentanyl), 10pg/mg (6-acetylmorphine, hydrocodone, methadone, morphine, norfentanyl, oxycodone, oxymorphone, and tramadol), or 100pg/mg (codeine and hydromorphone). The method was fully validated following the Scientific Working Group for Forensic Toxicology guidelines. The parameters evaluated were linearity, limit of detection and LOQ, imprecision, accuracy, carryover, matrix effects, extraction efficiency, process efficiency, interferences, and autosampler stability.
2020 American Academy of Forensic Science 72nd Annual Scientific Meeting in Anaheim, CA
February 17th–22nd: Anaheim Convention Center
Student: Christian Hopkins
Study: Further Evaluation of a Dry Vacuuming Technique for Recovery of DNA From Handwritten Documents
A John Jay team has developed a non-destructive homemade vacuum method for collecting biological material from handwritten documents that preserves the integrity of fingermark and indentation evidence. Currently forensic laboratory first process paper for indented writing, then for latent prints, but reversing this would increase DNA yields and minimize contamination. The method was evaluated on handwritten documents on different types of paper. The quantity of recovered DNA varied from donor to donor, but showed a trend correlated to the different sizes and surface properties of the tested paper types. Copy and notebook paper had the same size, but copy paper is rougher and yielded more DNA. Deposit slips with their smooth surface and small size had a very low DNA yield. The vacuum did not work well on manila envelopes as these were too thick to allow for air to pass through and the vacuum had less suction. Magazine paper is very thin and a difficult substrate. Friction ridge detail quality was not affected on either paper type and the new method proved to be feasible for non-destructive DNA collection.
2020 American Academy of Forensic Science 72nd Annual Scientific Meeting in Anaheim, CA
February 17th–22nd: Anaheim Convention Center
Student: Natalee Small-Davidson
Study: The Reproducibility of Individual DNA Deposits Detected With Diamond Dye
Contact traces are an important part of DNA casework in all crime laboratories and, with optimized recovery, detection, and interpretation methods, many samples now lead to positive associations to a person of interest. The probative value of these associations and the possibility of passive transfer need to be considered carefully and individual variation on how much DNA is left behind (shedding propensity) is an important factor. In 2018, Kanokwongnuwut et al. published a method for testing shedding variability based on DNA staining and cell counting, this project aimed at reproducing this work. Fingerprints were collected from unwashed and washed fingers in triplicate over three weeks. There was variation over the three weeks especially for unwashed fingers. It was possible to rank volunteers as heavy and low shedders. In conclusion: in our hands, the method was not as reproducible as described, but showed a similar distribution of heavy, intermediate, and light shedders.
Presented at the 2019 NEAFS Meeting in Lancaster, PA
November 12th–16th: The Lancaster Marriot
Student: Julian Beach
Study: The Relationship between Terminal Velocity and Glass Fracture via. 177 Caliber Steel BBs
Glass is an abundant material in the environment, and can also be an abundant material found at crime scenes. It may often be the only thing between a bullet and its intended target, which is where fractography is necessary. Fractography is the study of fractured materials, such as glass. The majority of bullets will perforate or shatter most categories of glass; however, in some cases, the bullet may not have sufficient energy to shatter the glass at all. Correlating the terminal velocity of the projectile to the degree of glass fracture can provide useful information regarding the muzzle-to-target distance for a particular firearm/ammunition/glass combination. The experimental methodology was developed through pilot studies covering suitable muzzle-to-target distance ranges, the number of pumps required to pressurize the air rifle propulsion system, and the means of measuring the ricochet distance for projectiles which do not perforate the glass substrate. The goal of this research was to characterize the relationship between impact velocity and glass fracture pattern which can be useful in crime scene reconstruction.
Presented at the 2019 NEAFS Meeting in Lancaster, PA
November 12th–16th: The Lancaster Marriot
Student: Jaclyn Beshlian
Study: A Microspectral Analysis of Synthetic Wig Fibers
An microspectrophotometer (MSP) enables the scientist to collect absorption and fluorescence spectra of colored samples without destroying the piece of evidence itself. The information can be used to distinguish fibers similar in color from each other. This study used an MSP determine whether differentiation between 20 visually similar light brown synthetic wig fibers was possible. Prior to any analysis with the MSP, the material of the fibers was verified through FT-IR ATR, as well as their optical properties. Using a lab-assembled MSP the absorbance measurements were obtained perpendicular and on a 45-degree angle to the polarizer. After the absorbance measurements were complete the fibers were then exposed to fluorescent light. The fluorescent lighting used contained a series of UV, blue, and green 102 excitation filter combinations. No single fiber displayed the exact same spectra to another, allowing differentiation. When combining the information obtained through the absorbance measurements and the three excitation filter combinations, differentiation of all 20 visually similar light brown synthetic wig fibers was achieved
Presented at the 2019 NEAFS Meeting in Lancaster, PA
November 12th–16th: The Lancaster Marriot
Student: Ashley Borrego
Study: An Exploration of Protein and DNA components in Fingerprint Components
The main focus of this project was to investigate the protein and DNA components in both sebaceous and eccrine fingerprints and explore a possible correlation to visual fingerprint residue. Twenty volunteers were instructed to touch their face to produce sebaceous prints, and five 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 density of cellular debris. The results of the study illustrated that sebaceous samples that sebaceous samples contained significantly more DNA than eccrine samples, while the number of proteins via mass spectrometry was similar. Accordingly, sebaceous samples had better STR results with 75% full profiles compared to the 20% full DNA profiles of eccrine samples. Linear regression results indicate a lack of correlation between cellular debris scores and DNA yields in sebaceous samples, a strong correlation between the cellular debris and DNA yield in eccrine samples, and moderate correlations between the cellular debris and number of proteins in both sample types. The results of this study provide additional information about donor variability/shedder status, and the content of DNA and proteins in fingerprint samples.
2019 Congress of the International Society for Forensic Genetics in Prague, Czech Republic
September 9th–13th: Prague Congress Center
Student: Tebah Browne
Study: Semi-Quantitative Detection of Signature Peptide in Body Fluids by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
This study covers a modified semi-quantitative approach to detecting signature peptides for body fluid identification. A liquid chromatography tandem mass spectrometer normally used for toxicology was adapted to detect target ion transitions for five semen or saliva specific peptides. Peptide concentrations were measured based on a mixture of synthetic peptide standards. Samples were processed using a three-hour trypsin digestion and Microcon membrane filtration. This method generates PCR compatible DNA and peptide fractions that can be typed without any further treatment. Preliminary validation tests covered stains on different substrates, semen/saliva mixtures, limit of detection, and repeatability. All signature peptides were present at different concentrations, varied amongst donors, and were tissue specific. Saliva peptides were detected at lower concentrations and had a higher limit of detection (LOD). Semen peptides had higher concentrations and were detected even as a minor component in a mixture. All semen peptides and all, but one, saliva peptides were detected on the various substrates. DNA fractions did not show signs of degradation or PCR inhibition. The results indicate that this assay is feasible for DNA and protein identification.
2019 NEAFS Meeting in Lancaster, PA
November 12th–16th: The Lancaster Marriot
Student: Dino Robinson
Award: George W. Chin Memorial Scholarship
Graduate Student, Dino Robinson, was honored with a George W. Chin Memorial Scholarship award at the 2019 North Eastern Association of Forensic Scientist Meeting. This award is given to students who display excellence in his/her academic program.
2019 Society of Forensic Toxicologists (SOFT) Meeting in San Antonio, TX
October 16th–18th: Grand Hyatt San Antonio
Student: Victoria Mei
Award: SOFT Educational Research Award
Study: Validation of a Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method for the Quantification of 13 Designer Benzodiazepines in Postmortem Blood
The ease of purchasing designer benzodiazepines on the internet has increased their misuse. Their use for drug-facilitated sexual assaults is a growing threat. Their use as an alternative to prescription benzodiazepines causes major safety concerns, because the lack of dosage information can lead to unintended overdoses, coma, or death at higher doses for self-medicating users. More data on the quantification of designer benzodiazepines in forensic cases are needed. The main objective of Ms. Mei’s study was to develop and validate a method for the determination of 13 designer benzodiazepines in postmortem blood, to add to the in-house method that already included a limited number of common designer benzodiazepines. The validated method succeeded to simultaneously identify all 13 designer benzodiazepines in blood using solid phase extraction (SPE) and a 13.5-minute analysis on the LC-MS/MS, and proved to be simple, reproducible, sensitive, and robust.
2019 American Academy of Forensic Science 71st Annual Scientific Meeting in Baltimore, MD
February 19th–22nd: Baltimore Convention Center
Student: Patrick McLaughlin
Study: Improved DNA Recovery from Handwritten Documents
When paper evidence is submitted for evidence recovery, a common practice is to prioritize the chemical or physical development of latent prints prior to attempting any of the various methods of DNA extraction from the prints. Areas of the periphery are commonly targeted for print visualization where people most commonly hold and lift sheets of paper. The written text is rarely considered an area of interest for criminalists but has the potential to retain “touch” DNA evidence deposited when the writer of scraped their hand across the page during the writing process. In this study we asked male and female volunteers to produce handwritten documents. Additionally, a “field case” study was performed where volunteers provided a writing sample prior to and after a mild aerobic exercise period. The writing samples were then vacuumed using an irradiated and trimmed glass pipette containing a moistened cotton Puritan swab with a vacuum hose attached to the narrow end of the pipette. The quantity of recovered DNA varied greatly from donor to donor, but most of the collected samples provided sufficient material to for STR typing and successful comparisons to the reference samples. This technique did not affect latent print and indented markings. Additionally, the process does not damage the document, which may be of importance for prosecutorial value and court demonstration.
Presented at the 2018 NEAFS Meeting in Bolton Landing, NY
October 23rd–27th – The Sagamore Resort
Students: Niti Dalal and Patrick McLaughlin, Mentor Mechthild Prinz
Study: Optimizing a method for DNA recovery while preserving latent prints on paper
The evidence in criminal cases like kidnapping, extortion and bank robberies often consists of handwritten paper documents where both latent print processing and DNA collection are important. This project tested a workflow, where adhesive tape and dry swabs were used to remove DNA from the surface of the paper without destroying the fingerprint pattern underneath. With a higher DNA yield and better success rates for fingerprints, tape was more suitable than swabs. Tape DNA collection even worked after latent prints had been made visible through fluorescent powder.
Presented at 2016 NEAFS Annual Meeting in Atlantic City. New Jersey
October 12th - 16th – Harrah’s Resort and Casino
Students: Melissa Branker, BSc; Jennifer Rosati, PhD
Study: The importance of resource quality and species interactions
on the colonization behavior of the black blow fly, Phormia regina (Meigen).
Within minutes after death, the process of decomposition occurs, which modifies the morphology and structure of a corpse (Campobasso et al, 2001). During decomposition, there are a wide variety of insect groups that arrive and utilize carrion with a distinct pattern of insect succession (Campobasso et al, 2001). There are many forensically important Dipteran species that are known to colonize a decomposing carcass during the early stages of decomposition, which include the families of Calliphoridae (blow flies), Sarcophagidae (flesh flies) and Muscidae (house flies). Within the first few hours post-mortem, blow flies are known to have high levels of recruitment to the resource (Campobasso et al, 2001). As a result, blow flies are commonly used as indicators to determine the minimum time of colonization (MTC); which can be helpful in post-mortem interval (PMI) estimations. However, the colonization behavior of these indicator species can be influenced by a variety of factors including oviposition preference (Campobasso et al, 2001), pheromone cues (Yang and Shiao, 2012, Akol et al 2013), bacterial cues (Lam et. al 2007, Zheng et al 2013) as well as inter- and intra- specific interactions. (Giao and Godoy, 2007, Yang and Shiao, 2012). This research utilized two forensically relevant blow fly species: Lucilia sericata (Meigen) and Phormia regina (Meigen) to examine the effects of resource quality and species interactions on the oviposition behavior of blow flies. We hypothesize that both resource quality and the presence of L. sericata eggs will alter the colonization behavior of P. regina.
Team Rosati pictured in front of Melissa's poster on Forensic Entomology
(Graduate students Melissa Branker, Vincent Nappi, and undergraduate Veena Mehta)
54th Annual Meeting of TIAFT
Brisbane, Australia
August 28th – September 1st, 2016
Student: Briana Miller
Study: Stability of Synthetic Cathinones in Preserved Oral Fluid Specimens
Dr. Nikolas Lemos wanted to commemorate the 20th anniversary of his graduation from John Jay with a master’s degree in Forensic Science, and honor his late mentor, Professor Agarwal by sponsoring a current graduate student to attend the 2016 meeting of TIAFT, to be held in Brisbane, Australia. Briana Miller was that lucky student and she had the opportunity to present her paper on “Stability of Synthetic Cathinones in Preserved Oral Fluid Specimens”.
Presented at the American Association for Crime Scene Reconstruction Training Conference
2016 in Clark, New Jerey
Students: Tara Goldfrank; Peter Diaczuk, PhD
Study: Critical Angle Determination & Angle of Ricochet on Windshield Glass
Bullet trajectories are a critical element in crime scene reconstruction.
This study explores the variability of ricochet angles specifically for
windshields since shooting events often include vehicles.
Presented at the Eastern Analytical Symposium and Exposition,
2014 in Somerset, NJ
Students: Kristi Tami; Gloria Proni, Phd.
Study: Spectroscopic Characterization of Organophosphate Compounds
Most commercially important insecticides and lethal chemical warfare agents belong to the category of organophosphate compounds. Their mode of action is related to the accumulation of acetylcholine at the synapses that culminates in respiratory failure and neurological damage. We are investigating the toxicity of selected organophosphate compounds in respect to their structures' spatial differences.
Presented at the 66th Annual Scientific Meeting of the American Association of Forensic Science, 2014 in Seattle, WA.
Students: Theron Ng-A-Qui, B.S.; Bruce Eng, J.D.; Shu-Yuan Cheng, Ph.D.
Study: Extraction process efficiency study of cathinones by solid phase extraction
This study explored current limitations when dealing with synthetic drugs. Despite the increased availability of designer drugs, few studies have focused on the analytical extraction techniques for their detection and quantification in biological samples. With solid phase extraction (SPE) being the most commonly used technique for sample preparation, it is important to know the rate at which the target substances are being recovered. The results indicate that the Strata X Drug B SPE extraction was able to recover higher percentage of cathinone and mephedrone at medium (100 ng/ml) and high (500 ng/ml) concentrations, but not at low (10 ng/ml) concentration.
Presented ath the 2013 NEAFS Annual Meeting
September 25th – 28th, 2013, in Cromwell, CT
Student: Laura Pritchard
Study: Establishing a method to determine the Statistical Value of Fiber Evidence
Recent MS-FOS graduate Laura Pritchard presented her poster on "Establishing a method to determine the Statistical Value of Fiber Evidence". Dryer lint from 14 dryers was collected to show that each crime scene can be unique. A sample from each was mounted on its own microscope slide and then analyzed with a polarized light microscope. Color, cross sectional shape, parallel refractive index, perpendicular refractive index, dichroism, and birefringence of each fiber in the sample sets were captured and data were analyzed using Fisher’s Exact test. Her mentor for this project was Professor John Reffner.
