Image matching algorithms for breech face marks and firing pins in a database of spent cartridge cases of firearms

On the market several systems exist for collecting spent ammunition data for forensic investigation. These databases store images of cartridge cases and the marks on them. Image matching is used to create hit lists that show which marks on a cartridge case are most similar to another cartridge case. The research in this paper is focused on the different methods of feature selection and pattern recognition that can be used for optimizing the results of image matching.The images are acquired by side light images for the breech face marks and by ring light for the firing pin impression. For these images a standard way of digitizing the images used. For the side light images and ring light images this means that the user has to position the cartridge case in the same position according to a protocol. The positioning is important for the sidelight, since the image that is obtained of a striation mark depends heavily on the angle of incidence of the light. In practice, it appears that the user positions the cartridge case with +/-10 degrees accuracy.We tested our algorithms using 49 cartridge cases of 19 different firearms, where the examiner determined that they were shot with the same firearm. For testing, these images were mixed with a database consisting of approximately 4900 images that were available from the Drugfire database of different calibers.In cases where the registration and the light conditions among those matching pairs was good, a simple computation of the standard deviation of the subtracted gray levels, delivered the best-matched images. For images that were rotated and shifted, we have implemented a "brute force" way of registration. The images are translated and rotated until the minimum of the standard deviation of the difference is found. This method did not result in all relevant matches in the top position. This is caused by the effect that shadows and highlights are compared in intensity. Since the angle of incidence of the light will give a different intensity profile, this method is not optimal.For this reason a preprocessing of the images was required. It appeared that the third scale of the "à trous" wavelet transform gives the best results in combination with brute force. Matching the contents of the images is less sensitive to the variation of the lighting.The problem with the brute force method is however that the time for calculation for 49 cartridge cases to compare between them, takes over 1 month of computing time on a Pentium II-computer with 333MHz. For this reason a faster approach is implemented: correlation in log polar coordinates. This gave similar results as the brute force calculation, however it was computed in 24h for a complete database with 4900 images.A fast pre-selection method based on signatures is carried out that is based on the Kanade Lucas Tomasi (KLT) equation. The positions of the points computed with this method are compared. In this way, 11 of the 49 images were in the top position in combination with the third scale of the à trous equation. It depends however on the light conditions and the prominence of the marks if correct matches are found in the top ranked position. All images were retrieved in the top 5% of the database. This method takes only a few minutes for the complete database if, and can be optimized for comparison in seconds if the location of points are stored in files.For further improvement, it is useful to have the refinement in which the user selects the areas that are relevant on the cartridge case for their marks. This is necessary if this cartridge case is damaged and other marks that are not from the firearm appear on it.     

Human Y-specific STR haplotypes in a Slovenian population sample

The allele distribution of the systems DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385 and YCAII were investigated in a sample of 121 unrelated males from Slovenia     

Autobrewing revisited: endogenous concentrations of blood ethanol in residents of the United Arab Emirates.

Endogenous ethanol concentrations in blood were determined by sensitive headspace gas chromatography/mass spectrometry in 1557 residents of the United Arab Emirates. The subjects were from 13 nationalities, of both sexes and of different age groups. There was no significant difference in blood ethanol concentration between nationalities or between sexes within and between nationalities. The data was pooled and the overall median, minimum, maximum, 25% percentile and 75% percentile were 0.04, 0.00, 3.52, 0.01 and 0.09 mg/dl respectively. The values of blood ethanol concentration as reported in this study indicate that they are far too low to have any forensic significance.     

Long‐Run Labor Market Effects of the Job Corps Program: Evidence from a Nationally Representative Experiment

Job Corps is the nation's largest and most comprehensive career technical training and education program for at‐risk youth ages 16 to 24. Using the sample from a large‐scale experiment of the program from the mid‐1990s, this article uses tax data through 2015 (20 years later) to examine long‐term labor market impacts. The study finds some long‐term beneficial effects for the older students, with employment gains of 4 percentage points, 40 percent reductions in disability benefit receipt, and 10 percent increases in tax filing rates in 2015. For these students, program benefits exceeded program costs from the social perspective. This study is the first to establish that a national program for disconnected youth can produce long‐term labor market gains, and can be a positive investment made for society. The results suggest that intensive, comprehensive services that focus on developing both cognitive and noncognitive skills are important for improving labor market prospects for this population.     

A rare case of lethal methadone intoxication of a 3-week-old infant

The authors describe a rare case of lethal methadone intoxication of a 3-week-old infant. Born of a drug-addicted mother who was undergoing methadone substitution therapy, the newborn presented withdrawal symptoms and was immediately admitted to a paediatric ward where it was treated for 3 weeks, without administration of methadone. The infant died during bottle feeding within 24 h following discharge home.A post-mortem examination was performed as well as histopathological, toxicological and genetic tests were carried out in order to establish the cause and mode of death.The autopsy revealed obstruction of the lower air passages by stomach contents along with classical features of asphyxia. Toxicological tests revealed high concentrations of methadone and its metabolite in blood and urine as well as presence of methadone in stomach contents, and the DNA polymorphism analysis of the (sex-specific) amelogenin locus gave a negative result.On the basis of the results of the post-mortem examination, the laboratory tests and the police investigation, it was concluded that the drug was ingested with the bottle milk, and the possibility of administration of methadone at the hospital or its ingestion with the breast milk was precluded. Though both the cause and mode of death were established, the public prosecutor discontinued proceedings in the case due to inability to find the perpetrator.     

Identification and analyses of female civilian victims of the 1991 war in Croatia from the Glina and Petrinja areas

Introduction

The process of recovering and identifying human remains from individual and mass graves has proven to be the most effective method of resolving the fate of missing individuals in the former Yugoslavia. These efforts have two primary objectives: medicolegal—to identify the cause of death, and humanitarian—to bring closure to living family members, thus supporting the human rights of both the living and the deceased. From 1996 to the present, the remains of 388 individuals killed during the 1991 War in Croatia were recovered from the Glina and Petrinja areas (Sisa?ko–Moslova?ka County). The purpose of this paper is to report on the demographic and taphonomic characteristics of the recovered remains, and identify factors responsible for the discrepancy in the identification ratios.

Methods

To identify factors potentially responsible for the noted discrepancy, data were collected on the taphonomic characteristics of the recovered remains, the types of burials, as well as the factors responsible for positive identification. These factors included: forensic DNA testing, dental criteria, special signs (healed fractures, etc.), clothing and personal artifacts.

Results

The age distributions between males and females in the sample are significantly different. The mean age-at-death for males is 51.6 years, for females 67.0 years. In both sexes the majority of identifications (62.9% in females and 45.9% in males) were established through a combination of biological and non-biological features. In terms of the types of graves from which the bodies were recovered, positive identification in both sexes was lowest in mass graves (61.2% for males, and 84.2% for females). Females from mass graves were, however, better preserved than males—36.6% of males recovered from mass graves were completely skeletonized, while the same was true for only 19.3% of females (χ² = 7.06, P < 0.029). Completely skeletonized remains were identified in only 65.1% of cases, while partially skeletonized and saponified bodies were identified in 80.1% of cases.

Conclusion

Since positive identification in both sexes is strongly correlated with preservation of the bodies, the reason why female identification frequencies in the Glina and Petrinja regions are higher than male frequencies lies in the fact that females recovered from mass graves were better preserved than males recovered from mass graves. Identification of the factors responsible for this is a challenge that needs to be resolved in future studies.     

The chemical interconversion of GHB and GBL: forensic issues and implications.

In this work, the interconversion of GHB and GBL in a variety of aqueous media was studied. The effects of solution pH and time were determined by spiking GHB or GBL into pure water and buffered aqueous solutions, and determining the GHB and GBL contents at various time intervals. The degree of GBL hydrolysis to GHB was determined for several commercial aqueous-based GBL products, and further studied as a function of time. The effects of temperature and time were also determined for five commercial beverages spiked with GHB or GBL. GHB and GBL contents were determined using high performance liquid chromatography (HPLC). GHB and/or GBL confirmations were made using gas chromatography-mass spectrometry (GC-MS) and/or infrared spectroscopy (IR). Solution pH, time, and storage temperature were determined to be important factors affecting the rate and extent of GBL hydrolysis to GHB. Under strongly alkaline conditions (pH 12.0), GBL was completely converted to GHB within minutes. In pure water, GBL reacted to form an equilibrium mixture comprising ca. 2:1 GBL:GHB over a period of months. This same equilibrium mixture was established from either GHB or GBL in strongly acidic solution (pH 2.0) within days. A substantial portion of GBL (ca. 1/3) was hydrolyzed to GHB in aqueous-based GBL products, and in spiked commercial beverages, after ambient storage for a period ranging from several weeks to several months. Heat increased and refrigeration decreased the rate of GBL hydrolysis relative to ambient conditions. These studies show that hydrolysis of GBL to GHB does occur in aqueous-based solutions, with samples and time frames that are relevant to forensic testing. Implications for forensic testing and recommendations are discussed.     

The Decline of Federalism and the Rise of Morality-Policy Conflict in the United States

Morality policies-such as those pertaining to abortion, capitalpunishment, gambling, gay rights, pornography, and sex education—generateconflict over core values. These policies tend to be technicallysimple, potentially salient to the general public, and involvehigher than normal levels of citizen participation. They are,therefore, highly susceptible to being thrust into the activephase of policymaking when an incongruity develops between publicopinion and public policy. The reservation of authority to thestates on these issues embodied in the Tenth Amendment to theU.S. Constitution allows for closer policy-opinion congruence,therefore stabilizing morality policy politics. However, recentfederal actions on a range of morality policies have thrustthese issues onto the active political agenda of the states.     

Reluctant policy innovation through profit concession and informality tolerance: A strategic relational view of policy entrepreneurship in China's urban redevelopment

This paper engages with the theoretical perspective of policy entrepreneurship to examine the pattern and process of policy change in the context of China's urban redevelopment. Drawing upon a strategic-relational reinterpretation of policy entrepreneurship, this paper identifies a distinctive form of reluctant policy innovation in the “three old renewals” scheme initiated in Guangzhou where profit concession and informality tolerance were practiced to create a small window of opportunity for the project of urban redevelopment to break ground. The motivation of policy entrepreneurship in the successful urban renewal projects in Guangzhou was heavily contingent upon the geographically important location of the project site and the historically incidence of hosting the 2010 Asian Games, which forced municipal government to become entrepreneurial and innovative in decision making and income redistribution in order to get things done as quickly as possible. The distinct fashion of policy innovation identified in the case of Guangzhou points to the polymorphous and dynamic nature of policy entrepreneurship and advocates a relational treatment of the strategies and motives of policy entrepreneurs embedded in concrete geographical and historical context.