A re-examination of the MMPI-2 aggressiveness and immaturity indices in law enforcement screening

This study reports an analysis of Bartol's (1991) Immaturity Index and Hargrave and associates' (1988) Aggressiveness Index as a measure of police conduct. The correlations between the supervisory ratings and the Immaturity and Aggressiveness indices were examined for 1020 law enforcement officers. The results showed that Immaturity Index was related to termination for failure to complete training and insubordination. The Aggressiveness Index was related to a termination for failure to complete training and several other problematic police behaviors, but was not found to be specifically linked with acts of aggression. Implications for using these two indices in law enforcement selection are discussed. Authors' Note: Cary Rostow, Ph.D. is president of Matrix, Inc., Baton Rouge, Louisiana, and is in private practice in Baton Rouge. Robert Davis, Ph.D., is executive vice-president and director of science, research, and development for Matrix, Inc., and has a private practice in Baton Rouge. James B. Pinston, Ph.D., is a clinical neuropsychologist within the department of neurology at the Louisiana State University Health Sciences Center and School of Medicine in Shreveport, Louisiana. Dennis R. Combs, Ph.D., is an assistant professor of psychology at the University of Tulsa. Dennis R. Dixon, M.A., is currently a doctoral student at Louisiana State University.     

STR analysis of artificially degraded DNA-results of a collaborative European exercise

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.