DNA mixtures in forensic casework: a 4-year retrospective study

Occasionally interpretation guidelines from validation studies are difficult to apply to real forensic casework, especially in the case of mixed samples. Exogenous contamination, an unknown number of contributors or unbalanced proportion of each one in the sample and a varied degree of degradation of the biological materials, contribute to the difficulties in the interpretation of sample profiles. In this paper we have reviewed all the mixed genetic STR profiles encountered in our laboratory over 4 years (1997-2000) and evaluated the problems in the interpretation of the results. From 1547 criminal cases with 2424 samples typed, 163 showed a mixed profile (6.7%). We have observed that occasionally, a mixture appeared in the same sample with one multiplex amplification kit (e.g. Blue) and not with another (e.g. Green). From our results, it can be suggested that technical characteristics of the different fluorochrome groups in the multiplexes override the molecular characteristics of each STR in their capacity to detect mixtures.     

Age estimation by IBAS image analysis of teeth

The study of teeth to estimate age in a cadaver or in remains has become widely accepted in legal medicine, especially since the appearance of Gustafson's work in 1950. However, many studies published since that time have questioned the accuracy of these determinations. Computerized image analysis (IBAS) provides much more precise measurements of the parameters involved in these studies. An IBAS I (Kontron) image analysis system was used to study 19 different morphological parameters in midsagittal sections of a total of 173 upper and lower central incisors from as many live subjects. The data thus obtained provide useful information for determining the subject's age.     

Equal employment opportunity across states: The EEOC 1979–1989

This study uses unpublished EEOC data from 1979–89 to concentrate on how dwindling resources and policy changes advocated by the EEOC chairs regarding the time and intensity devoted to anti-discrimination cases may have yielded regional variation in discrimination outcomes. We arrive at two major conclusions. First, evidence here suggests that the EEOC counteracted potential regional resistance against anti-discrimination laws. Second, we argue that the seeming inefficiency of the EEOC during Thomas' first years as EEOC chair appears to have occurred because he inherited a large pool of low-merit cases.