Internal Validation of the AmpFlSTR Yfiler™ Amplification Kit for Use in Forensic Casework

Abstract:  Y-chromosomal short-tandem repeat (Y-STR) amplification has been used in forensic casework at the Bureau of Criminal Apprehension (BCA) Forensic Science Laboratory since 2003. At that time, two separate amplifications were required to type the SWGDAM recommended loci (DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS438, and DYS439). The Yfiler™ kit coamplifies these loci as well as DYS437, DYS448, DYS456, DYS458, DYS635, and Y GATA H4. The Yfiler™ kit was validated following the internal validations outlined in the SWGDAM revised validation guidelines. Our studies show that 0.125 ng of male DNA will generate a complete 17 locus profile and that as little as 0.06 ng of male DNA yields an average of nine loci. In the male–male mixtures, a complete profile from the minor component was detected up to 1:5 ratio; most of the alleles of the minor component were detected at a 1:10 ratio and more than half the alleles of the minor component were detected at a 1:20 ratio. Complete YSTR profiles were obtained when 500 pg male DNA was mixed with female DNA at ratios up to 1:1000. At ratios of 1:5000 and 1:10,000 (male DNA to female DNA) inhibition of the YSTR amplification was evident. The YSTR results obtained for the adjudicated case samples gave significantly more probative information than the autosomal results. Our studies demonstrate that the Yfiler™ kit is extremely sensitive, does not exhibit cross-reactivity with female DNA, successfully types male DNA in the presence of overwhelming amounts of female DNA and is successful in typing actual forensic samples from adjudicated cases.     

Engaging Frontline Workers in Times of Organizational Change

In "Beyond Cognition: Affective Leadership and Emotional Labor," Professors Newman, Guy, and Mastracci further the discussion of contemporary leadership by exploring leadership transitions in public agencies that serve vulnerable populations, such as the abused elder, the neglected child, or the court-involved teenager.     

Troubled Children and Children in Trouble: Redefining the Role of the Juvenile Court in the Lives of Children

This Essay considers the emerging research in the area of dual‐jurisdiction children, often referred to as “crossover kids”—those currently or previously involved in maltreatment proceedings who have also committed delinquent acts. Part I describes the development of the juvenile courts in the early twentieth century. Part II of this Essay questions the need to “track” children along one legal path or another and points to the pitfalls of providing services to some children through a criminal justice paradigm instead of treating all children through a social work paradigm. Finally, Part III advocates a redesign of the juvenile court—a return to its roots—to better enable a court to consider the needs of the whole child, in context with the needs of her/his family.     

Book Review

Understanding criminal behaviour, psychosocial approaches to criminality D. W. Jones Devon: Willan Publishing, 2008.     

From population- to subject-based limits of T/E ratio to detect testosterone abuse in elite sports

In elite sports, indirect testing of testosterone abuse is mainly based on the testosterone over epitestosterone (T/E) ratio. Since this marker is characterized by a small ratio of intra- to inter-individual variation, it is surprising that current anti-doping strategy uses a screening test based on a population-based limit. From a database of more than 15,000 steroid profiles obtained from routine controls, the collection of steroids profiles of 11 elite athletes followed during 2 years, and a longitudinal study involving 17 amateur athletes, 8 of which were orally administrated testosterone undecanoate pills, we selected 12 case studies to represent the possible scenarios to which the anti-doping laboratories are confronted. Various detection strategies at the disposal of the laboratories are employed and discussed, including isotope ratio mass spectrometry (IRMS) analysis and a Bayesian interpretation of the T/E-time profile. The weak sensitivity versus specificity relation of a population-based limit for the T/E ratio is outlined. As a result, we propose a Bayesian screening test whose T/E threshold progressively evolves from a population basis to a subject basis as the number of individual test results increases. We found that this screening test heightens drastically the capacity to detect testosterone abuse, at no additional financial and administrative expenses for anti-doping authorities.