The role of sexual interests and situational factors on rapists' modus operandi: Implications for offender profiling

Purpose. Although it has often been suggested that there is a direct relationship between an individual's sexual interests and behaviours exhibited during the crime they commit, few studies have investigated this question empirically. The purpose of the present study was thus to examine the role of sexual interests and situational factors as to their possible relationship to three components of rapists' modus operandi: (a) the level of organization of the offence, (b) the level of force used by the offender, and (c) the level of injury inflicted on the victim during the sexual assault. Methods. This study is based on a sample of 118 offenders who sexually assaulted a female aged 16 or over. All participants were assessed phallometrically and through the CQSA, a computerized questionnaire. Data were analysed using multiple regression analyses. Results. Our findings showed links between sexual interests, situational factors, and rapists' modus operandi. Firstly, individuals demonstrating a greater sexual interest in nonsexual violence showed a higher level of organization in the modus operandi. Secondly, alcohol consumption prior to the offence was related to a higher level of coercion. Finally, a negative emotional state prior to the crime was related to a high level of injury inflicted on the victim. Conclusions. Despite the fact that several authors postulated a direct link between the offender's sexual interests and his behaviour at the crime scene, our results only partially support this hypothesis. Moreover, our results partly support the fact that crime scene behaviour is related to offenders' personal characteristics, challenging an assumption of criminal profiling. We still believe that the modus operandi is related to offenders' personal attributes. It is, however, dynamic and may fluctuate due to certain situational factors related to offenders and victims. Future studies should take into account situational factors related to offenders and their victims.     

Forensic analysis of commercial petroleum products using selective fluorescence quenching.

A novel method for the forensic analysis of commercial petroleum products is presented. In this approach, the petroleum sample is extracted with nitromethane and then separated by capillary liquid chromatography with laser-induced fluorescence detection. The addition of selective fluorescence quenching agents allows the sample to be profiled by the distribution of alternant and nonalternant polycyclic aromatic hydrocarbons (PAHs). In preliminary studies, the quenching behavior of nitromethane and diisopropylamine was established by using a standard mixture of sixteen PAHs ranging in size from two to six aromatic rings. Subsequent examination of new and used motor oil demonstrated that characteristic differences arise in the PAH content, which may allow for the unique identification of oil from a particular engine or vehicle. In addition, three brands of petrolatum jelly were successfully distinguished. Although a number of alternant alkylated and heterocyclic PAHs were found in all petrolatum samples, there were significant differences in the relative concentrations of alternant as well as nonalternant PAHs. This allowed for clear differentiation of the samples through qualitative inspection of their chromatograms as well as quantitative statistical correlation techniques.     

Associating gunpowder and residues from commercial ammunition using compositional analysis

Qualitatively identifying and quantitatively determining the additives in smokeless gunpowder to calculate a numerical propellant to stabilizer (P/S) ratio is a new approach to associate handgun-fired organic gunshot residues (OGSR) with unfired powder. In past work, the P/S values of handgun OGSR and cartridges loaded with known gunpowders were evaluated. In this study, gunpowder and residue samples were obtained from seven boxes of commercial 38 caliber ammunition with the goals of associating cartridges within a box and matching residues to unfired powders, based on the P/S value and the qualitative identity of the additives. Gunpowder samples from four of the seven boxes of ammunition could be easily differentiated. When visual comparisons of the cartridge powders were considered in addition to composition, powder samples from all seven boxes of ammunition could be reliably differentiated. Handgun OGSR was also collected and evaluated in bulk as well as for individual particles. In some cases, residues could be reliably differentiated based on P/S and additive identity. It was instructive to evaluate the composition of individual unfired gunpowder and OGSR particles. We determined that both the numerical centroid and dispersity of the P/S measurements provide information for associations and exclusions. Associating measurements from residue particles with those of residue samples collected from a test firing of the same weapon and ammunition appears to be a useful approach to account for any changes in composition that occur during the firing process.     

Determination of sex by discriminant function analysis and stature by regression analysis: a lateral cephalometric study

Determination of sex and estimation of stature from the skeleton is vital to medicolegal investigations. In the present study, an attempt is made to determine sex and estimate stature of an individual using data derived from lateral cephalogram in Central Indian population. Skull is composed of hard tissue and is the best preserved part of skeleton after death, hence, in many cases it is the only available part for forensic examination. Lateral cephalogram is ideal for the skull examination as it gives details of various anatomical points in a single radiograph, also it easily provides architectural and morphological details of skull superstructures and intra-cranial details for comparisons. A discriminant function derived from 10 cephalometric variables provided 99% reliability in sex determination. The formulae obtained from regression analysis using the maximum length of skull showed very high degree of reliability for estimation of stature in males as well as females.     

The effect of luminol on presumptive tests and DNA analysis using the polymerase chain reaction.

This study was designed to test the following factors involved with processing luminol treated bloodstained evidence: 1) The reactivity of other presumptive chemical color tests, phenolphthalin (PT) and tetramethylbenzidine (TMB), following the application of the light emitting luminol presumptive test. 2) The effect of different cleanings of various bloody substrates on the luminol test. 3) The effect of different cleanings of various bloody substrates on the ability to obtain DNA suitable for PCR testing. 4) The ability to extract DNA from luminol treated bloodstained substrates using three extraction techniques. 5) The effect of spraying washed and unwashed bloodstains on various substrates with luminol on the ability to correctly type the DNA using PCR. Our findings indicated that luminol did not adversely effect the PCR testing and did not interfere with the PT and TMB presumptive tests for blood. It was determined that the substrate and the method of cleaning were the major factors affecting DNA yield and the ability to type the bloodstains using PCR based technologies.     

Crime prevention and commercial Burglary: A time series analysis

The impact of crime prevention on commercial burglary in a section of Portland, Oregon is assessed. Using time series analysis, and a control area for comparison, some of the problems of previous crime prevention research are addressed. The results of the study discussed show that not only was there a significant reduction in commercial burglary, but the effect persisted. Several rival hypotheses which could explain this reduction are rejected and suggestions for future research are offered.     

Skeletal identification by radiographic comparison: blind tests of a morphoscopic method using antemortem chest radiographs

This study investigated the value of antemortem (AM) and postmortem (PM) radiographs of the claviculae and C3-T4 vertebrae to identify skeletons of missing U.S. soldiers from past military operations. In total, 12 field-recovered skeletons and AM chest radiographs of 1460 individuals were used. For each skeleton, examiners analyzed an array of AM chest radiographs (up to 1000 individuals) and attempted to identify the correct PM/AM radiographic match. When examiners were able to compare all images within a single test, only true-positive identifications were made. When AM radiographs were presented one-at-a-time, in sequential order, and without examiners having knowledge of array size, erroneous identifications resulted but they were almost exclusively made by untrained examiners (accuracy = 35% vs. 90% for trained examiners). This study demonstrates the value of chest radiographs for the identification of disarticulated and even eroded skeletons, but only when methods are wielded by trained examiners.     

A comparison of the ability of experts and non-experts to differentiate between adult and child human bite marks using receiver operating characteristic (ROC) analysis

Fifty colour prints of human bite marks were sent to 109 observers who were asked to decide using a six point rating scale, whether the marks had been produced by the teeth of an adult or a child. The observers consisted of accredited senior forensic dentists, accredited junior forensic dentists, general dental practitioners, final year dental students, police officers and social workers. The results were compared against a “gold standard” which was the actual verdict from the case. Comparison of the results between the groups of observers and the standard was made using Receiver Operating Characteristics (ROC) methodology. The best decisions were made by senior/junior experts or final year dental students. General dental practitioners and police officers were least able to differentiate correctly between adult and child bite marks. The effect of training is important and its effects need to be assessed in more detail in future studies.     

Most-favored-nation clauses in commercial contracts: legal and economic analysis and proposal for a guideline

The prevalent use of “most favored nation” (MFN) clauses in commercial agreements has garnered significant attention in the economics and legal literature and by practitioners and enforcement agencies. From an antitrust standpoint, there is a strong consensus that while MFN provisions can lead to procompetitive outcomes or at least play a competitively neutral role, they may also result in competitive harm and a loss of consumer welfare. Therefore, US and EU enforcement agencies and courts have held that MFNs should be reviewed on a case-by-case basis, considering the specific characteristics of both the contractual provision and the industry. While a case-by-case approach is valid, it is not ideal from a variety of standpoints: that of the competition authorities seeking to make best use of their limited resources and that of practitioners seeking to advise their clients. Accordingly, published guidelines on the use of MFNs, containing presumptions and safe harbors, would be both efficient and useful. The paper argues that it would increase the efficiency and accuracy of antitrust enforcement if one of the leading competition authorities issued MFN guidelines. The paper suggests a set of presumptions and safe harbors that should be included in any such guidelines.     

Linking ammonium nitrate-aluminum (AN-AL) post-blast residues to pre-blast explosive materials using isotope ratio and trace elemental analysis for source attribution

Forensic science practitioners are often called upon to attribute crimes using trace evidence, such as explosive remnants, with the ultimate goal of associating a crime with a suspect or suspects in order to prevent further attacks. The explosive charge is an attractive component for attribution in crimes involving explosives as there are limited pathways for acquisition. However, there is currently no capability to link an explosive charge to its source via post-blast trace residues using isotope ratios or trace elements. Here, we sought to determine if pre-blast attribution signatures are preserved after detonation and can be subsequently recovered and detected. A field study was conducted to recover samples of post-blast explosives from controlled detonations of ammonium nitrate-aluminum (AN-Al), which were then analyzed via isotope ratio mass spectrometry (IRMS) and inductively coupled plasma-mass spectrometry (ICP-MS) for quantitation and profiling of isotopes ratio and trace element signatures, respectively. Oxygen and nitrogen isotope ratios from AN-Al yielded some of the most promising results with considerable overlap within one standard deviation of the reference between the spreads of pre- and post-blast data. Trace element results from AN-Al support the findings in the isotope ratio data, with 26 elements detected in both pre- and post-blast samples, and several elements including B, Cd, Cr, Ni, Sn, V, and Zn showing considerable overlap. These preliminary results provide a proof-of-concept for the development of forensic examinations that can attribute signatures from post-blast debris to signatures in pre-blast explosive materials for use in future investigations.     

Measuring the intercondylar shelf angle using radiographs: intra- and inter-observer error tests of reliability

This study presents a test of intra- and inter-observer measurement error rates of the intercondylar shelf angle of the distal femur, as measured on lateral radiographs. This measurement is the central element of a method to determine racial affiliation from the distal femur. Four observers independently radiographed a set of 33 complete and partial femora from collections housed at the Joint POW/MIA Accounting Command, Central Identification Laboratory. Each observer then measured the intercondylar shelf angles in each radiograph, following the original method's guidelines. A supplementary inter-observer error test was conducted by four additional observers on one set of radiographs. Statistically significant differences were found for both intra- and inter-observer error based on the results of Student's t-tests, paired samples t-tests, and ANOVA analyses. The results of this study indicate that further experimentation should be undertaken in order to develop refined measurement techniques that may help improve standardization and reduce the observer error rates.     

Recognition by forensic facial approximation: case specific examples and empirical tests

The skeletal remains of one individual found near Adelaide in 1994, although not known at the time, were the first evidence of what was to be a serial killing reported to have resulted in the highest casualty list to date in Australia (12 victims). Since the usual methods of identification could not be used or were unsuccessful on these remains, facial approximations were produced and advertised over the 4-year period following their discovery, in an attempt to help to identify them. However, no identification was made. In 1999, the remains were reported to be identified by radiographic comparison. Approximately 3 months before this identification was made, another facial approximation was produced by the first author (CNS), but this face was never advertised in the media. Although rarely reported in the literature, this paper provides an example where facial approximation methods were not successful in a forensic scenario. The paper also reports on empirical tests of the facial approximation created by the first author to determine if this facial approximation might have been useful had it been advertised. The results provide further evidence that high resemblance of a facial approximation to the target individual does not indicate recognizability, as the facial approximation was poorly recognized even though it bore good resemblance to the target individual. The usefulness of facial approximation techniques is discussed within the context of this case and more broadly. Methods used to assess the accuracy of facial approximations are also discussed and further evaluated.     

A rapid method for blood alcohol determination by headspace analysis using an electrochemical detector.

A method for the determination of blood alcohol concentration by headspace analysis using an electrochemical detector is described. A determination can be made within 2 min, and only 0.1 ml of blood is required for each analysis. The detector response was linearly related to ethanol concentrations up to 3.0 mg/ml. The standard deviation of a single determination was +/- 0.014 mg/ml. The accuracy of the method based on comparison with an enzymatic (alcohol dehydrogenase) technique was high, the mean recovery being 102.2% of the attributed concentration. The ease of the operation and fast analysis time make the method ideal for serial determinations, for example during mass screening of biological samples for ethyl alcohol in forensic and toxicology laboratories.     

Delayed ethanol analysis of breath specimens: long-term field experience with commercial silica gel tubes and breathalyzer collection

Delayed ethanol analysis was performed on breath specimens collected with commercial silica gel tubes using multiple Breathalyzer instruments. Eleven hundred and nine results were obtained from an ethanol testing program over a five-year period. Only 2.5% of the specimens had apparent collection errors. For the valid specimens, the most frequent result was 0.11 g/210 L and the mean result was 0.14 g/210 L. For 642 specimens, delayed results were compared with direct results. Direct results were greater than delayed results for 55%, less than for 27%, and equal to for 18% of the pairs. When fixed tolerance limits of +/- 0.03 were used, 81% of the direct results were confirmed. The confirmation percentage was best in the critical range of direct results, 0.05 to 0.15 g/210 L. The collection tubes showed no substantial variability in retaining ethanol during storage and releasing ethanol for analysis.     

Oil price shocks and stock market returns of the GCC countries: empirical evidence from quantile regression analysis

This paper examines the effects of oil price shocks on the stock market returns of the Gulf Cooperation Council countries. The empirical method used is quantile regression analysis. In addition, we allow for structural breaks and asymmetry by differentiating between positive and negative oil price changes. Unlike OLS analysis, quantile regression allows the coefficient estimates to vary throughout the distribution of the dependent variable, which provides a complete picture of the relationship between the explanatory variables and the dependent variable. Our results suggest that the coefficient estimates have not been constant throughout the distribution of stock returns; that oil price shocks have asymmetrical effects on stock returns; and that the effects of oil price shocks on stock market returns are affected by stock market conditions. Overall, the results suggest that rising oil prices increase stock returns only when stock markets are bullish (high quantiles) and normal (medium quantiles), and that falling oil prices lower stock returns only when stock markets are bearish (low quantiles) and normal (medium quantiles). This suggests that oil and stock markets are more likely to boom together or crash together.     

Bullet identification: a case of a fatal hunting accident resolved by comparison of lead shot using instrumental neutron activation analysis.

Bullet identification by chemical analysis often provides a powerful clue in forensic science. A case is reported in which a hunting accident was resolved by using instrumental neutron activation analysis (INAA) for direct comparison of the trace element content in lead shot. Different preparation batches of lead shot appear to have a high within-group composition homogeneity, and good differentiation is achieved between different batches. Determination of the nickel and antimony content on a bush branch demonstrated that the branch had been perforated by one of the shot pellets, and this helped the detectives in reconstruction of the crime scene.     

The estimation of the time of death by non-protein nitrogen (NPN) in cadaveric materials. Report 3: Multiple regression analysis of NPN values in human cadaveric materials

The non-protein nitrogen (NPN) values in brain, lung, liver, and kidney in 79 autopsy cases were determined according to the Micro-Kjeldahl Nessler method. Multiple regression analysis of the data was performed with every possible combination of the time of death and the NPN values in the tissues.The brain NPN showed the best correlation with the postmortem time (r = 0.673), whereas the other correlations were less satisfactory (lung r = 0.422, liver r = 0.397, and kidney r = 0.379, respectively). However, multiple combinations of each tissue NPN value proved to give better correlation coefficients and smaller errors of the estimated time of death.The practical significance of the tissue NPN as a postmortem biochemical indicator of the time of death and the multiple regression analysis of such indicators were extensively discussed in this report.     

Manipulation by algorithms. Exploring the triangle of unfair commercial practice,data protection,and privacy law

The optimisation of sales practices in consumer markets through machine learning not only harbours the potential to better match consumer preferences with products, but also risks to facilitate the exploitation of consumer weaknesses discovered via data analysis. More specifically, recent technological advances have brought us to the edge of mind-reading technologies, which automatically analyse mental states and adapt offers accordingly, in potentially manipulative ways. This article shows that, in market contexts, the challenges of manipulation by algorithm necessitate an integrated understanding of unfair commercial practice, data protection, and privacy law. It maps the interactions between these contiguous yet distinct fields of law, and draws on economics and computer science to develop a novel framework to deal with algorithmic influence. Furthermore, it critically discusses the Commission proposals for the Digital Services Act and the Artificial Intelligence Act, and suggests to complement them with more broadly applicable measures to mitigate algorithmic manipulation.     

Nondiscrimination on the basis of disability by public accommodations and in commercial facilities--Department of Justice. Final rule

This rule implements title III of the Americans with Disabilities Act, Public Law 101-336, which prohibits discrimination on the basis of disability by private entities in places of public accommodation, requires that all new places of public accommodation and commercial facilities be designed and constructed so as to be readily accessible to and usable by persons with disabilities, and requires that examinations or courses related to licensing or certification for professional and trade purposes be accessible to persons with disabilities.