U.S. flag
      An official website of the United States government, Department of Justice.
        Here's how you know
      Here's how you know**Official websites use .gov**
            
            A **.gov** website belongs to an official government organization in the United States.
      **Secure .gov websites use HTTPS**
            
            A **lock** (
            A locked padlock
            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Menu

      
        close

            
            
                                              About NIJ
        
                    
  
          About NIJ
      
    
          The NIJ Director
          How NIJ Is Organized
          Mission and Guiding Principles
          Research and Development Process
          Strategic Framework
          Assessments of NIJ
          Annual Reports & Reports to Congress
          Staff Directory
          Funding & Awards
        
                    
  
          Funding & Awards
      
    
          Current Funding
          Forthcoming Funding
          Expired Funding
          Awards: Listing of Funded Projects
          Guidance for Applicants and Awardees
          Fellowship & Student Programs
          Travel Scholarships
          NIJ Challenge Program
          Library & Multimedia
        
                    
  
          Library & Multimedia
      
    
          NIJ Journal
          Podcasts
          Publications Listing
          Multimedia Listing
          Rated Practices on CrimeSolutions
          Rated Programs on CrimeSolutions
          Software & Databases
          Datasets
          Patents
          Topics
        
                    
  
          Topics
      
    
          Article Listing
          Corrections
          Courts
          Crime Prevention
          Crimes
          Drugs and Crime
          Equipment and Technology
          Forensic Sciences
          Youth Justice
          Justice System Reform
          Law Enforcement
          Tribal Crime and Justice
          Victims of Crime
          Events
        
                    
  
          Events
      
    
          NIJ 2024 Research Conference
          Scheduled Events
          On-Demand Events
          Research Meetings & Workshops
          NIJ-Hosted Online Training

                            
                                About
          Contact Us
          Subscribe
          Topics A-Z
                  Share
FacebookXLinkedInRedditPinterestEmail Home
                            Events
 Rapid and Effective Identification of Organic and Inorganic Gunshot Residues Event Dates
              November 20, 2019, 1:00 pm
 – 2:30 pm
Event Duration
              90 minutes
Location
              Online

Register

Forensic laboratories and law enforcement personnel provide valuable support in the reconstruction of events and the assessment of the value of evidence in firearm-related investigations. The scientific validity of this field relies on extensive research and standardization of the existing methods (i.e., ASTM  1588-17 SEM-EDS). Nonetheless, there are still some challenges in this arena in terms of speed of analysis, preservation of evidence, accuracy, and interpretation of results. The main goal of this webinar is to present a discussion of the current state of gunshot residue (GSR) detection and efforts being made to improve current capabilities.

This webinar presents the development and validation of novel methods to identify organic and inorganic gunshot residues.  Electrochemical and laser-based spectroscopic techniques (LIBS) are presented as screening methods that are quicker, more selective, and more powerful than any current field-testing technique. The analysis is conducted sequentially on universal SEM-EDS carbon-stub adhesives, in less than 5 minutes per sample, and with minimal destruction of the sample. These methods offer superior information via simultaneous detection of organic and inorganic components and identification of a significant number of elements used in modern ammunition (standard and “green” non-toxic ammunition).

The proposed methodologies were validated through a set of 500 samples and in-house GSR control standards. In this study, authentic samples were collected from hands traced from background populations and from the hands of shooters who fired a gun.  These screening methods demonstrated low false positives and false negatives. Information on inorganic GSR and organic GSR markers was possible on the same sample, with accuracy greater than 87%. Moreover, LIBS can generate 3D-chemical images of the spatial distribution of GSR on the sample for enhanced confidence in the results. These methods have the potential to be adopted in forensic laboratories and the field, with the capability to accelerate response time and reduce backlogs and unnecessary incarceration costs.

Also, a novel LC/MS method that utilizes crown ether complexation for inorganic and organic detection was optimized as a modern tool for confirmation purposes and to cross-validate the performance of the screening tests. These assays are expected to offer a cost-effective approach to complement the traditional SEM-EDS method widely utilized in forensic laboratories.

The resulting data was assessed using different statistical approaches—critical threshold, Logistic Regression, Naïve Bayes, and Neural Networks —to examine the performance of each method alone and collectively. Experiments were designed to assess error rates, selectivity, sensitivity, and accuracy. Probabilistic assessments from population studies are anticipated to assist forensic examiners and the trier of fact to make informed decisions about the significance of the evidence.

**Detailed Learning Objectives:**

Understand challenges faced in the forensic analysis and interpretation of gunshot residues and how emerging technologies can provide viable solutions.
	Recognize the main capabilities and limitation of electrochemistry, LIBS and LC/MS for GSR detection and their potential impact to the criminal justice.
	Identify the value of using populations that simulate casework samples for the validation and assessment of performance measures of qualitative data.
View the Recorded Seminar
  
  
          Details
Event Type
              Webinar
    Event Option(s)
          Online,
                        On demand

Sponsor(s) / Host(s)

National Institute of Justice (NIJ), U.S. Department of Justice;Forensic Technology Center of Excellence
    Contact
          NIJ Forensic Technology Center of Excellence

  Link
              If you have questions about this course, contact the FTCoE.

  Registration Dates
              October 14, 2019 - November 20, 2019

  Registration Status
              Open

  Eligibility
              Free and open to all.

  Credits
              Certificate of completion
    
  
Read more about
    
            Performance measures
        Forensic laboratories
        Logistic Regression
        Forensic sciences
        Law enforcement personnel
        Gunshot residue
        Laser-induced breakdown spectroscopy (LIBS)
        Forensic examiners
        Gunshot sensors
        Evidence preservation
        Evidence analysis
        Trace evidence
        Gun violence
        Evidence analysis and processing
        Firearms
        Firearm identification
  
Date Created: October 16, 2019
    
          Side navigation
  

        

  
  
              NIJ 2024 Research Conference
    
      
            
            
            
      Scheduled Events
    
      
            
            
            
      On-Demand Events
    
      
            
            
            
      Research Meetings & Workshops
    
      
            
            
            
      NIJ-Hosted Online TrainingSimilar Events
        
                      DEIA: What I learned from the AAFS Diversity Outreach Committee
                  Discovery, Disclosure and Ethical Considerations
 Top

      National Institute of Justice

        
        
                        About NIJ
                    About NIJ
      
    
                  How NIJ Is Organized
      
    
                  NIJ Director
      
    
                  Research Disclaimer
      
    
                  Funding & Awards
                    Funding & Awards Home
      
    
                  Awards Listing
      
    
                  Current Funding
      
    
                  Guidance for Applicants and Awardees
      
    
                  Resources
                    Events
      
    
                  Podcasts
      
    
                  Publications
      
    
                  Topics
      
    
                  Multimedia
      
    
                  Reuse Policy
      
    
                  Contacts
                    Contact NIJ
      
    
                  Staff Directory
      
    
                  Submit a FOIA Request
      
    
                  File a Civil Rights ComplaintFacebook
          
                      X
          
                      YouTube
  

      810 7th St. NW, Washington, D.C. 20531
      
              Secondary Footer link menu
            Accessibility
              Plain Language
              Privacy Policy
              Legal Policies and Disclaimer
              No FEAR Act
              Freedom of Information Act
              USA.gov
              Justice.gov