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                            Library & Multimedia
 Relaxing the assumption of unrelatedness in the numerator and denominator of likelihood ratios for DNA mixtures
NCJ Number
              303997
Journal

*Forensic Science International - Genetics* Volume: 51 Dated: 2021
Author(s)
          Paul Stafford Allen;
                        Simone N .Pugh;
                        Jo-Anne Bright;
                        Duncan A. Taylor;
                        James M. Curran;
                        Zane Kerr;
                        John S. Buckleton
Date Published

March 2021
Annotation
              This study conducted a small, preliminary examination of the potential effect of relaxing the assumption that in a DNA mixture, donors are unrelated to each other.
Abstract
              DNA mixtures will have multiple donors under both the prosecution and alternate propositions when assigning a likelihood ratio for forensic DNA evidence. These donors are usually assumed to be unrelated to each other. The current study considered the simple situation of a two-person mixture with no dropout and a two-person major/minor mixture with dropout of the minor contributor. No adjustment was made for subpopulation effects. Mixtures were simulated under the assumptions that the donors were siblings or that they were unrelated. Both unresolvable and major/minor mixtures were considered. The likelihood ratio was compared assuming sibship with the likelihood ratio assuming no relatedness. The LR for hypotheses assuming no relatedness was less than the LR assuming relatedness approximately 95 percent of the time when relatives were present in the mixture. (publisher abstract modified)
      
  
          Additional Details
Grant Number(s)
        2017-DN-BX-0136
                                2020-DQ-BX-0022


  
  
        
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  Publication Type
        Research (Applied/Empirical)


  
  
        
  Award
        Population Genetic Issues for Forensic DNA Profiles
                                Population Genetic Issues for Forensic DNA Profiles
    
  
  
Date Published: March 1, 2021
    
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