MSGID: 1:317/3 64a79517   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    Forensics lab cracks case on newer, 'greener' gunshot residue    
      
     Date:   
         July 6, 2023   
     Source:   
         West Virginia University   
     Summary:   
         Discoveries by forensic scientists about how gunshot residue behaves   
         on skin, hair and fabric will allow crime scene investigators   
         to catch up to the proliferation of new, eco-friendly types of   
         ammunition and make faster, more informed decisions at crime scenes   
         and in forensic laboratories.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
      
   ==========================================================================   
   FULL STORY   
   ==========================================================================   
   Discoveries by West Virginia University forensic scientists about how   
   gunshot residue behaves on skin, hair and fabric will allow crime scene   
   investigators to catch up to the proliferation of new, eco-friendly   
   types of ammunition and make faster, more informed decisions at crime   
   scenes and in forensic laboratories.   
      
   Lead and other toxic components of ammunition are crucial in establishing   
   the presence of gunshot residue, or GSR, at crime scenes. However,   
   heavy metals like lead aren't present in new "green" ammunitions that   
   are changing the rules for GSR analysis, according to Tatiana Trejos,   
   associate professor in the Eberly College of Arts and Sciences Department   
   of Forensic and Investigative Science.   
      
   "A major forensics discovery was that, when you fire a gun, a cloud of   
   particles is produced by the primer, the material that explodes and causes   
   a bullet to eject. The primer contains, among other things, inorganic   
   compounds, heavy metals like lead, barium, antimony," Trejos said.   
      
   "When this cloud touches our skin, tiny particles remain there. The   
   composition of those particles is specific to firearm discharge -- we   
   don't commonly find that combination of metals in other conditions. That   
   realization was a big help to forensic scientists in firearms-related   
   investigations."  But over the years, ammunition has changed. More primers   
   are manufactured without metals harmful to the environment and human   
   health. That's a challenge for GSR analysis and the reason forensic   
   science -- a field that uses scientific methods to help solve crimes   
   and examine trial evidence -- is looking beyond inorganic compounds like   
   metals to organic compounds like nitroglycerine that are also released   
   when a gun fires.   
      
   "If we combine information about organic and inorganic compounds in GSR,   
   we can have more confidence in our results," Luis Arroyo, an analytical   
   chemist and associate professor, said. "For over a decade, scientific   
   groups have said we need to know more about organic gunshot residue. We're   
   missing opportunities to confirm the presence of GSR, and this research   
   funded by the National Institute of Justice is helping to narrow that   
   gap."  The research establishes how organic and inorganic compounds in   
   GSR differ in the ways they each persist on surfaces and transfer to   
   other surfaces during activities like running, hand shaking or washing.   
      
   Trejos and Arroyo published the results of the studies in a Forensic   
   Chemistry paper co-authored with WVU graduate students Courtney Vander   
   Pyl, Kourtney Dalzell, Korina Menking-Hoggatt and Thomas Ledergerber.   
      
   To gather data, the team created new and improved organic and inorganic   
   GSR "reference standards" or methodologies for creating standardized   
   mixes of particles that accurately mirror real-world gunshot residue,   
   allowing different labs to meaningfully compare results.   
      
   They applied those particles to fabrics, to the skin and hair of real   
   human volunteers and to an artificial skin product called Strat-M. Then   
   they subjected those surfaces to real and simulated activities like   
   running, struggling, washing and rubbing, before measuring the remaining   
   particles.   
      
   Trejos said the experiments established Strat-M as a viable substitute   
   for human skin.   
      
   "Artificial skin has been used by fields like pharmaceuticals, cosmetics,   
   health sciences. Now we have proved it can provide a consistent forensic   
   standard while allowing us to test conditions that wouldn't be feasible or   
   safe for a person's skin."  The researchers found inorganic GSR particles   
   persist longer on a surface -- a palm, a sweatshirt -- than organic   
   compounds, but they're more susceptible to being lost or transferred   
   by common activities. A shooter who washes their hands with soap and   
   water, then dries them with a paper towel, will likely prevent crime   
   scene investigators from identifying GSR based on analysis of lead,   
   barium and antimony particles on their hands.   
      
   The fact that inorganic particles persist over time and are significantly   
   lost only due to outside forces can be critical to questions about   
   whether someone is the victim of a suicide or homicide, Trejos said.   
      
   Organic compounds, conversely, may be lost from clothing if a suspect   
   struggles during arrest, but they are less likely to transfer to someone   
   else, like the arresting officer.   
      
   Up to 100 characteristic inorganic particles could transfer from one   
   person to another during a handshake, compared to no transfer at all   
   for organic compounds. But unlike inorganic particles, organic particles   
   are lost over time due to factors like evaporation from the skin.   
      
   Trejos said the next step is to put the findings to use in combination   
   with another methodology the group recently developed, which allows   
   field CSIs to immediately analyze possible GSR at a crime scene.   
      
   As enthusiastic as Trejos is about the research, she emphasizes that   
   real-life CSIs don't have as many answers as the ones on television.   
      
   "Right now, we can do a pretty good job answering the question, 'Is   
   GSR present or not?' But the next and more interesting question is,   
   'Did this person fire the gun?' Forensics is not always able to answer   
   that with high certainty. This research opens new avenues to answer   
   questions relevant to a judge or jury.   
      
   "By providing faster and more informative investigative tools, we're   
   helping to apprehend offenders with more solid evidence, and we're   
   minimizing the potential for false incarcerations."   
       * RELATED_TOPICS   
             o Health_&_Medicine   
                   # Forensics # Skin_Care # Cosmetics   
             o Matter_&_Energy   
                   # Forensic_Research # Chemistry # Organic_Chemistry   
             o Science_&_Society   
                   # Justice # Legal_Issues # STEM_Education   
       * RELATED_TERMS   
             o Forensics o Hair o Forensic_toxicology o Identity_theft o   
             Prison o Acne o Hair_follicle o Parachute   
      
   ==========================================================================   
      
    Print   
      
    Email   
      
    Share   
   ==========================================================================   
   ****** 1 ****** ***** 2 ***** **** 3 ****   
   *** 4 *** ** 5 ** Breaking this hour   
   ==========================================================================   
       * First_Snapshots_of_Fermion_Pairs *   
       Why_No_Kangaroos_in_Bali;_No_Tigers_in_Australia   
       * New_Route_for_Treating_Cancer:_Chromosomes *   
       Giant_Stone_Artefacts_Found:_Prehistoric_Tools   
       * Astonishing_Secrets_of_Tunicate_Origins *   
       Most_Distant_Active_Supermassive_Black_Hole *   
       Creative_People_Enjoy_Idle_Time_More_Than_Others   
       * Restoring_Fragile_X_Protein_Production *   
       Earth's_Solid_Metal_Sphere_Is_'Textured' *   
       Elephants_Vary_Their_Dinner_Menu_Day-To-Day   
      
   Trending Topics this week   
   ==========================================================================   
   SPACE_&_TIME Asteroids,_Comets_and_Meteors Big_Bang Jupiter   
   MATTER_&_ENERGY Biochemistry Construction Engineering_and_Construction   
   COMPUTERS_&_MATH Educational_Technology Communications   
   Mathematical_Modeling   
      
      
   ==========================================================================   
      
   Strange & Offbeat   
   ==========================================================================   
   SPACE_&_TIME   
   Quasar_'Clocks'_Show_Universe_Was_Five_Times_Slower_Soon_After_the_Big_Bang   
   First_'Ghost_Particle'_Image_of_Milky_Way   
   Gullies_on_Mars_Could_Have_Been_Formed_by_Recent_Periods_of_Liquid_Meltwater,   
   Study_Suggests MATTER_&_ENERGY Holograms_for_Life:_Improving_IVF_Success   
   Researchers_Create_Highly_Conductive_Metallic_Gel_for_3D_Printing   
   Growing_Bio-Inspired_Polymer_Brains_for_Artificial_Neural_Networks   
   COMPUTERS_&_MATH   
   Number_Cruncher_Calculates_Whether_Whales_Are_Acting_Weirdly   
   AI_Tests_Into_Top_1%_for_Original_Creative_Thinking   
   Displays_Controlled_by_Flexible_Fins_and_Liquid_Droplets_More_Versatile,   
   Efficient_Than_LED_Screens Story Source: Materials provided by   
   West_Virginia_University. Note: Content may be edited for style and   
   length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Courtney Vander Pyl, Kourtney Dalzell, Korina Menking-Hoggatt,   
      Thomas   
         Ledergerber, Luis Arroyo, Tatiana Trejos. Transfer and persistence   
         studies of inorganic and organic gunshot residues using synthetic   
         skin membranes. Forensic Chemistry, 2023; 34: 100498 DOI: 10.1016/   
         j.forc.2023.100498   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/07/230706152735.htm   
      
   --- up 1 year, 18 weeks, 3 days, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 218/700 226/30 227/114   
   SEEN-BY: 229/110 112 113 307 317 400 426 428 470 664 700 291/111 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45 5075/35   
   PATH: 317/3 229/426