Secondary DNA transfer by working gloves.

With the development of highly sensitive STR profiling methods, combined with sound statistical tools, DNA analysis on the (sub-)source level is hardly ever seriously questioned in court. More often, the exact mode of DNA transfer to the crime scene is questioned. In burglary cases, in particular when gloves are worn, secondary DNA transfer is often discussed as explanation for finding a DNA profile matching the accused because it is well known that gloves can act as a potential vector for indirect DNA transfer. In this study we investigated the shedder status as a possible factor influencing the extent of secondary DNA transfer to a crime scene, with the person committing the crime wearing working gloves. Firstly, the shedder status for 40 participants (20 male, 20 female) was determined, following a previously published procedure. Good shedders (n = 12) were found to deposit a higher amount and quality of DNA onto objects, compared to bad shedders (n = 25). Secondly, participants were paired into four groups (good with good; good with bad; bad with good; bad with bad), each group consisting of five pairs. The first participant (P1) of each pair used working gloves to pack and carry a box to simulate a house move. Two days later, the second participant (P2) of the pair wore the same pair of gloves to simulate a burglary, using a screwdriver as a break-in tool. After taking swabs of the outside and inside of a glove (primary DNA transfer) and the handle of the screwdriver (secondary DNA transfer), full DNA analysis was performed. Our experiments show that good shedders, overall, deposit more DNA than bad shedders, both onto the outside and the inside of the glove, regardless of being P1 or P2. When conducting the experiments with two participants sharing the same shedder status, no significant differences occurred in the number of deposited alleles. In six out of 19 cases a DNA profile matching P1 was found (binary LR>106) on the screwdriver and in all six cases P1 was a good shedder. Our results indicate that the shedder status of an individual affects the extent of DNA transfer. They further confirm the possibility of an innocent person's DNA profile being found on an object they never handled.

International comparisons of behavioral and emotional problems in preschool children: parents' reports from 24 societies.

International comparisons were conducted of preschool children's behavioral and emotional problems as reported on the Child Behavior Checklist for Ages 1½-5 by parents in 24 societies (N = 19,850). Item ratings were aggregated into scores on syndromes; Diagnostic and Statistical Manual of Mental Disorders-oriented scales; a Stress Problems scale; and Internalizing, Externalizing, and Total Problems scales. Effect sizes for scale score differences among the 24 societies ranged from small to medium (3-12%). Although societies differed greatly in language, culture, and other characteristics, Total Problems scores for 18 of the 24 societies were within 7.1 points of the omnicultural mean of 33.3 (on a scale of 0-198). Gender and age differences, as well as gender and age interactions with society, were all very small (effect sizes < 1%). Across all pairs of societies, correlations between mean item ratings averaged .78, and correlations between internal consistency alphas for the scales averaged .92, indicating that the rank orders of mean item ratings and internal consistencies of scales were very similar across diverse societies.