Forensic integrity verification of video recordings based on MTS files

Digital video is used in criminal trials as evidence with legal responsibility because video content vividly depicts events occurring at a crime scene. However, using sophisticated video editing software, assailants can easily manipulate visible clues for their own benefit. Therefore, the integrity of digital video files acquired or submitted as evidence must be ensured. Forensic analysis of digital video is key to ensuring the integrity of links with individual cameras. In this study, we analyzed whether it is possible to ensure the integrity of MTS video files. Herein, we propose a method to verify the integrity of MTS files encoded by advanced video coding high definition (AVCHD), which is frequently used for video recording. To verify MTS file integrity, we propose five features. Codec information, picture timing, and camera manufacture/model are modified AVI and MP4-like format video verification features. Group of pictures and Universally Unique Identifier patterns were specifically developed for MTS streams. We analyzed the features of 44 standard files recorded using all recording options of seven cameras. We checked whether integrity can be validated on unmanipulated videos recorded in various environments. In addition, we considered whether manipulated MTS files edited in video editing software could be validated. Experimental results show that all unmanipulated and manipulated MTS files with known recording devices were discriminated only when all five features were checked. These results show that the proposed method verifies the integrity of MTS files, strengthening the validity of MTS file-based evidence in trials.     

Piercing the surface: A mechanical analysis of stabbing with household tools

Estimating the applied power during a stabbing incident, or estimating the minimal force necessary to penetrate the body with a certain weapon is a challenging task in forensic practice. A thorough forensic evaluation of stabbing forces needs objective numerical experimental data. Stabbing tests of 12 different weapons – including knives, a pair of scissors, a fork, screwdrivers, a rasp, a corkscrew, and a utility knife blade – were performed with a Mecmesin MultiTest-dV material tester on pork loin and ballistic gel to estimate the stabbing forces and dynamics. Penetration force (F_p) and maximal force (F_max) were recorded, and the registered force curves were analyzed. F_max was 159.8–212.07 Newton (N), 30.56–30.58 N, 168.9–185.48 N for various knives; 171.39–190.43 N for the pair of scissors, 233.6 N for the fork; 532.65–562.65 N, 370.31–367.19 N and 314.51–432.89 N for various screwdrivers, 44.14–56.62 N for utility knife during pork loin stabbing. The butter knife, corkscrew and rasp were not able to penetrate the pork loin, and the curved fork bent during stabbing. The results prove that weapon characteristics greatly influence the force necessary for penetration. Maximal stabbing force depends mostly on tip sharpness, and the force sharply decreases after penetration occurs, which indicates that edge sharpness is not as important as tip characteristics during stabbing perpendicular to skin surface. The penetration force during stabbing with a pair of scissors is comparable to the penetration force of knives. Stabbing with screwdrivers generally needs larger force than average knives but depends greatly on screwdriver size.     

Pulp volume quantification methods in cone-beam computed tomography for age estimation: A critical review and meta-analysis

The secondary dentin deposition that occurs after the tooth formation process results in a decrease in pulp cavity volume in adolescents and adults. The purpose of this critical review was to correlate pulpal and/or dental volume on cone-beam computed tomography (CBCT) with chronological age approximation. A subobjective was to investigate which methodology and CBCT technical parameters would be most appropriate to evaluate this correlation. This critical review followed the PRISMA guidelines, and it was conducted by a search through PubMed, Embase, SciELO, Scopus, Web of Science, Cochrane Library databases, as well as gray literature. Primary studies that used pulp volume, or pulp chamber to tooth volume ratio measured using CBCT were included. Seven hundred and eight indexed and 31 non-indexed records were identified. A qualitative analysis was performed including 25 selected studies with a total of 5100 individuals, age ranging from 8 to 87 years without sex predilection. The most used method was pulp volume/tooth volume. CBCT voxel size ranged between 0.09 and 0.5. Manual segmentation associated with threshold algorithms was used in most of the studies. Correlation between the pulp volume/tooth volume ratio was moderate: −0.66 for the upper central incisors, −0.59 for upper canines and −0.56 for lower canines. High heterogeneity was observed among the studies. It is concluded that pulp volume should be used with caution in age estimation. Evidence supports the preferable use of upper incisors with pulp volume/tooth volume ratio for age estimation. There is not enough evidence that voxel size interferes in age estimation by pulp volume.     

Accountability from the perspective of the forum: citizens’ attitudes towards accountability in Europe

The aim of this article is to analyse citizens’ attitudes towards governmental accountability in 24 European countries and to examine the influence of contextual and individual factors on perceptions of accountability. Using as a dataset the 2012 European Social Survey, the results show that citizens respond positively when the media provides reliable information on which to judge the government, when individuals perceive that governments perform well, when individuals live in more extensive and generous welfare states and when they live in countries where the rule of law is firmly established. In addition, the findings also provide evidence that compared to politically left-wing citizens, right-wing supporters have, on average, a higher perception of governmental accountability. In particular, the findings show strong positive evaluations of right-wing governments by right-wing voters in comparison with left-wing governments by left-wing voters.     

We All Need Help: “Big Data” and the Mismeasure of Public Administration

Rapid advances in our ability to collect, analyze, and disseminate information are transforming public administration. This “big data” revolution presents opportunities for improving the management of public programs, but it also entails some risks. In addition to potentially magnifying well‐known problems with public sector performance management—particularly the problem of goal displacement—the widespread dissemination of administrative data and performance information increasingly enables external political actors to peer into and evaluate the administration of public programs. The latter trend is consequential because external actors may have little sense of the validity of performance metrics and little understanding of the policy priorities they capture. The author illustrates these potential problems using recent research on U.S. primary and secondary education and suggests that public administration scholars could help improve governance in the data‐rich future by informing the development and dissemination of organizational report cards that better capture the value that public agencies deliver.     

Performance Federalism and Local Democracy: Theory and Evidence from School Tax Referenda

Federal governments are increasingly employing empirical measures of lower‐level government performance to ensure that provincial and local jurisdictions pursue national policy goals. We call this burgeoning phenomenon “performance federalism” and argue that it can distort democratic accountability in lower‐level elections. We estimate the impact of a widely publicized federal indicator of local school district performance—one that we show does not allow voters to draw valid inferences about the quality of local educational institutions—on voter support for school tax levies in a U.S. state uniquely appropriate for this analysis. The results indicate that a signal of poor district performance increases the probability of levy failure, a substantively large and robust effect that disproportionately affects impoverished communities. The analysis employs a number of identification strategies and tests for multiple behavioral mechanisms to support the causal interpretation of these findings.     

Debating rape jokes vs. rape culture: framing and counter-framing misogynistic comedy

ABSTRACT

Humor controversies can simultaneously reveal and obscure relations of power, as well as the rhetorical/political nature of jokes. US comedian Daniel Tosh ignited one such controversy in July 2012 when he directed a rape joke toward a female audience member during a live performance in Hollywood, CA. This paper consists of a two-part analysis of this humor controversy. First, we examine a televised debate following this incident, between a comedian and feminist, to map the dominant framing and counter-framing of rape jokes. We contend these positions are representative of two frames that repeatedly surface in response to controversial sexist humor: a dominant patriarchal frame and an oppositional feminist counter-frame. Second, we analyze the saliency of these two frames among college students to observe the way individual interpretations resonate with, challenge, and complicate those frames. In light of our findings, we argue the dominant framing/interpretation of rape jokes reinforce patriarchal and free-market ideologies, and deny real-world implications of misogynistic humor, particularly when comedians/audiences defend such jokes as harmless fun.     

Substate variations in political values in Canada

The article aims to make three methodological and substantive contributions to the literature on substate cleavages in political values. Considerable controversy characterizes this literature. The paper argues that this controversy is due to how indicators representing political values are chosen and constructed. The paper proposes to use factor analysis to select and construct indicators of political values. The analysis identifies five dimensions, which collectively account for 57% of Canadians’ political values. They include support for moral traditionalism, egalitarianism, pluralism, openness to immigration and personal responsibility. Second, the paper shows that there is only limited variation across provinces in political values. Third, the paper shows that this result holds when considering regional variations rather than provincial variations.