Estimate of the random match frequency of acquired characteristics in a forensic footwear database

When analyzing footwear impression evidence, a significant task of the forensic examiner is to determine if a questioned impression could have originated from a known shoe. To form this opinion, examiners typically evaluate the similarity, quantity, and quality of shared class characteristics and characteristics of use. Since these criteria are developed through training and experience, and therefore purported to be subjective in nature, the opinions formed regarding footwear evidence can be misunderstood. One way to mitigate this criticism is to complement casework with research that includes quantitative analyses. The aim of this study was to estimate random match frequency of randomly acquired characteristics (RAC-RMF) in a research database comprised of 1,300 outsoles with more than 80,000 RACs. Based on a combination of visual comparisons (>91,000) and mathematical predictions (>3.8 million), results indicate that 32% of the outsoles in this dataset do not share any indistinguishable RAC pairs with each other, while 19% possess RAC-RMFs of 1 out of 1,299. At the other extreme, the maximum RAC-RMF observed was 49 out of 1,299. These results are based on high-quality test impressions, human assessments, and a single quantitative similarity metric, so they are considered specific to this dataset and method of analysis. Results could differ in other databases and with impressions of lower quality, and therefore should not be extrapolated to casework. Despite this limitation, the results provide a point of reference for how often RACs may repeat in position and geometry on non-mated outsoles, therefore forming the basis for future research.     

The Development and Application of Random Match Probabilities to Firearm and Toolmark Identification

The field of firearms and toolmark analysis has encountered deep scrutiny of late, stemming from a handful of voices, primarily in the law and statistical communities. While strong scrutiny is a healthy and necessary part of any scientific endeavor, much of the current criticism leveled at firearm and toolmark analysis is, at best, misinformed and, at worst, punditry. One of the most persistent criticisms stems from the view that as the field lacks quantified random match probability data (or at least a firm statistical model) with which to calculate the probability of a false match, all expert testimony concerning firearm and toolmark identification or source attribution is unreliable and should be ruled inadmissible. However, this critique does not stem from the hard work of actually obtaining data and performing the scientific research required to support or reject current findings in the literature. Although there are sound reasons (described herein) why there is currently no unifying probabilistic model for the comparison of striated and impressed toolmarks as there is in the field of forensic DNA profiling, much statistical research has been, and continues to be, done to aid the criminal justice system. This research has thus far shown that error rate estimates for the field are very low, especially when compared to other forms of judicial error. The first purpose of this paper is to point out the logical fallacies in the arguments of a small group of pundits, who advocate a particular viewpoint but cloak it as fact and research. The second purpose is to give a balanced review of the literature regarding random match probability models and statistical applications that have been carried out in forensic firearm and toolmark analysis.     

Comparisons of familial DNA database searching strategies

The current familial searching strategies are generally based on either Identity-By-State (IBS) (i.e., number of shared alleles) or likelihood ratio (i.e., kinship index [KI]) assessments. In this study, the expected IBS match probabilities given relationships and the logic of the likelihood ratio method were addressed. Further, the false-positive and false-negative rates of the strategies were compared analytically or by simulations using Caucasian population data of the 13 CODIS Short Tandem Repeat (STR). IBS ≥ 15, IBS ≥ 16, KI ≥ 1000, or KI ≥ 10,000 were found to be good thresholds for balancing false-positive and false-negative rates. IBS ≥ 17 and/or KI ≥ 1,000,000 can exclude the majority of candidate profiles in the database, either related or not, and may be an initial screening option if a small candidate list is desired. Polices combining both IBS and KI can provide higher accuracy. Typing additional STRs can provide better searching performance, and lineage markers can be extremely useful for reducing false rates.     

Using automated comparisons to quantify handwriting individuality

The proposition that writing profiles are unique is considered a key premise underlying forensic handwriting comparisons. An empirical study cannot validate this proposition because of the impossibility of observing sample documents written by every individual. The goal of this paper is to illustrate what can be stated about the individuality of writing profiles using a database of handwriting samples and an automated comparison procedure. In this paper, we provide a strategy for bounding the probability of observing two writers with indistinguishable writing profiles (regardless of the comparison methodology used) with a random match probability that can be estimated statistically. We illustrate computation of this bound using a convenience sample of documents and an automated comparison procedure based on Pearson's chi-squared statistic applied to frequency distributions of letter shapes extracted from handwriting samples. We also show how this bound can be used when designing an empirical study of individuality.     

Sports Journalists and Corruption in Zimbabwean Football: Reflections on the Asiagate Scandal

Zimbabwe experienced a high-profile football match fixing scandal between 2007 and 2010, commonly known as the Asiagate scandal. The men’s senior national football team – the Warriors – reportedly fell victim to Asian betting syndicates. Three journalists from the statecontrolled media were sanctioned by the Zimbabwe Football Association (ZIFA) for allegedly participating in the scandal. Burgeoning literature on “brown envelopes” and freebies in journalistic practice in Africa at large, and Zimbabwe in particular, has under-theorised this phenomenon in Zimbabwe’s sports journalism fraternity. Focusing on the Asiagate scandal, this article reports on a study that used the “brown envelope journalism” theoretical lens to examine the subject and its repercussions on sports journalism practice, from the view point of sports journalists. In-depth interviews were conducted with selected sports journalists both from the publicly owned and privately owned media in Zimbabwe. The article avers that due to the deteriorating socio-economic environment, some journalists were “seduced” by “brown envelopes” and “recruited” into a “patronage” corrupt network by match fixers. Consequently, “patronised” journalists became pliant tools in hands of match fixers and failed to “bark” at the malpractices masterminded by their “benefactors”.     

Photographic comparison of surface topography as a viable solution when physical match is challenging

Physical matching methods are a family of well‐known methods that are utilized in order to determine whether two pieces of a tearable/breakable material used to be one object. When performing physical match of polymers, it is sometimes difficult to reach an unambiguous conclusion. This is due to various reasons. One is when the tear/fracture resides in an inaccessible or hidden‐from‐view region of the piece. Another is when the shape of the tear/fracture at the object's tear/fracture line is insufficient for deducing a complete match. Third is deficiency of material along this line. These are examples of processes where the line is affected so drastically, so that a match renders impossible. Specifically, when addressing elastic materials, the tear/fracture line may even be squashed. This may also be a reason for difficulty in performing a physical match. In this paper, a method is proposed where a match is alternatively achieved by means of photographic comparison of marks on the surface topography of the pieces‐in‐question. Comparisons of pairs of torn pieces of silicon rubber were made. The procedure involved photography of the surface topography the pieces. Then, the photographs were horizontally mirror‐flipped. Lastly, a comparison was made between two photographs: a photograph of one piece and a mirror‐flipped photograph of the opposite piece. The results show that after comparing the pieces to one another, only one unique pair turned out to be positively matched. Using the proposed method, not only the comparison is done by a more informative method (comparing to physical match), it is also more convenient, faster, less expensive, and technically simpler.     

Intra-EU Labor Mobility: A Key Pillar of the EU Architecture Subject to Challenge

Intra-EU labor mobility is often characterized as a major contributor to better functioning European labor markets. Does the evidence of recent cross-border labor mobility support this positive expectation? Does the EU live up to its potential of being a role model by showing that managing free movement of labor in turbulent times is possible? We will show that, in spite of its potential, the challenges facing free movement of labour are tremendous. We address four important aspects: enlargement; transitional measures and their consequences; the crisis and its effects; and the potential offered by free movement for better labor allocation.     

A Physical Match of a Metallic Chip Found on a Bolt Cutters’ Blade

Bolt cutters are known as devices which are used for cutting hard objects and rigid materials such as padlocks and bars. They are commonly used in instances of forced entries. In this case study, a bolt cutter was found in the car of two suspects in a grocery burglary. This study indicates how the presence of a small metallic chip found on a suspected bolt cutter can prove that the tool was used in the crime scene. During the initial examination, a metallic chip from the cut shackle padlock was found stuck to one of the bolt cutters’ blades. By comparing the metallic chip's microscopic edge and the breaking (fracture) line of the padlock's shackle, a full physical match was noticed. We wish to report here how residue, even the smallest, can be used to link burglary tools to a crime scene with a high level of certainty.     

简论黑哨犯罪的定性及其应对建议

关于黑哨问题的争论到目前为止仍没有得出一个明确的定论,本文从犯罪主体角度出发,试提出对黑哨问题的个人看法。笔者认为黑哨裁判员的行为已经触犯了刑法,其身份和执法的性质决定了其行为的公务性,因此应当以受贿罪定罪和处罚。