High Resolution Imaging of Latent Fingerprints by Localized Corrosion on Brass Surfaces

Abstract:  The Atomic Force Microscope (AFM) is capable of imaging fingerprint ridges on polished brass substrates at an unprecedented level of detail. While exposure to elevated humidity at ambient or slightly raised temperatures does not change the image appreciably, subsequent brief heating in a flame results in complete loss of the sweat deposit and the appearance of pits and trenches. Localized elemental analysis (using EDAX, coupled with SEM imaging) shows the presence of the constituents of salt in the initial deposits. Together with water and atmospheric oxygen—and with thermal enhancement—these are capable of driving a surface corrosion process. This process is sufficiently localized that it has the potential to generate a durable negative topographical image of the fingerprint. AFM examination of surface regions between ridges revealed small deposits (probably microscopic "spatter" of sweat components or transferred particulates) that may ultimately limit the level of ridge detail analysis.     

A Comparison of Cleaning Regimes for the Effective Removal of Fingerprint Deposits from Brass

Abstract:  Effective removal of fingerprint deposits is crucial for experimentation related to the corrosion of metals by fingerprint deposits. Such removal is also necessary prior to deposition of test fingerprints. The effectiveness of four regimes in removing fingerprint deposits from brass is considered. Sustained wiping of the deposit with a tissue at applied pressures of up to c . 1430 Pa or rubbing while the brass was immersed in acetone both failed to remove completely all traces of fingerprint deposits. Heating the brass to 600°C was an effective remover; however, this also oxidized the surface of the metal except where inhibited by fingerprint deposits. The most effective regime, and the only one of the four that removed all traces of deposit without affecting the properties of the metal surface, was immersion in warm soapy water while rubbing with a tissue. We propose this as the preferred method for fingerprint removal.     

Analysis of Pigmented Inkjet Printer Inks and Printed Documents by Laser Desorption/Mass Spectrometry*,†

Abstract: Anyone with a computer, scanner, and color printer has the capability for creating documents such as identification cards, passports, and counterfeit currency. Laser desorption mass spectrometry (LDMS) has been demonstrated as a powerful tool for colorant analysis. Inkjet printers are now moving largely toward the use of pigments as colorants; their insolubility makes analysis by simpler methods such as thin‐layer chromatography no longer an option. Recent developments in pigmented inkjet printer inks, such as gloss optimizers that coat pigment particles, may prohibit colorant analysis by LDMS. We demonstrate here that pigments used in inks from two Epson printers can be detected and analyzed by LDMS. Also, LDMS spectra of various colors created using a 4‐cartridge (cyan/magenta/yellow/black, CMYK) inkset are evaluated, to begin to develop an approach for unraveling LDMS data from real samples, to determine the number of inks used by a printer, and the chemical composition of the colorants.     

Pilot Study of Automated Bullet Signature Identification Based on Topography Measurements and Correlations*†

Abstract: A procedure for automated bullet signature identification is described based on topography measurements using confocal microscopy and correlation calculation. Automated search and retrieval systems are widely used for comparison of firearms evidence. In this study, 48 bullets fired from six different barrel manufacturers are classified into different groups based on the width class characteristic for each land engraved area of the bullets. Then the cross‐correlation function is applied both for automatic selection of the effective correlation area, and for the extraction of a 2D bullet profile signature. Based on the cross‐correlation maximum values, a list of top ranking candidates against a ballistics signature database of bullets fired from the same model firearm is developed. The correlation results show a 9.3% higher accuracy rate compared with a currently used commercial system based on optical reflection. This suggests that correlation results can be improved using the sequence of methods described here.     

Sensitivity of the Luminol Test with Blue Denim

Abstract: An article appearing in this journal in 2000 suggested that the sensitivity of the luminol test performed on denim fabric is usually no greater than at a 1:100 dilution of blood. This study shows that the luminol test may be unambiguously interpreted at substantially greater dilutions of blood. In this study, four different types of denim were tested by spraying a swatch of fabric with a typical formulation of the luminol reagent. Testing was conducted of dilutions of blood up to 1:1000, all of which showed distinct chemiluminescence. Diluted blood was applied to denim material in the form of a random number. A successful test was obtained only when a “blind” observer, i.e., an observer who was uninformed of the number, correctly reported the number.     

Cultural Cognition and Public Policy: The Case of Outpatient Commitment Laws

What explains controversy over outpatient commitment laws (OCLs), which authorize courts to order persons with mental illness to accept outpatient treatment? We hypothesized that attitudes toward OCLs reflect “cultural cognition” (DiMaggio, P. Annl Rev Sociol 23:263–287, 1997), which motivates individuals to conform their beliefs about policy-relevant facts to their cultural values. In a study involving a diverse sample of Americans (N = 1,496), we found that individuals who are hierarchical and communitarian tend to support OCLs, while those who are egalitarian and individualistic tend to oppose them. These relationships, moreover, fit the cultural cognition hypothesis: that is, rather than directly influencing OCL support, cultural values, mediated by affect, shaped individuals’ perceptions of how effectively OCLs promote public health and safety. We discuss the implications for informed public deliberation over OCLs.     

Disseminated fungal infection with renal infarction simulating homicide

Renal infarction is an uncommon finding at autopsy most often related to occlusive thromboembolism or to trauma. A 42-year-old woman is reported who presented with persistent right flank pain after an alleged assault with injury to the area 3 weeks previously. Renal infarction necessitated a right nephrectomy that was followed by multiorgan failure and death. Given the possible link between the assault and the renal pathology, a homicide investigation was initiated. Although renal infarction had been confirmed by hospital pathologists, microscopy with special staining of both kidneys and the heart after autopsy revealed multifocal areas of angioinvasion by fungi having morphologic characteristics of mucormycosis. The only other finding of significance was alcohol-related micronodular cirrhosis of the liver. Renal infarction had therefore been caused by an angioinvasive fungal infection predisposed to by immunocompromise associated with alcoholism and not by trauma-induced arterial dissection. This case demonstrates that careful histological assessment of tissues from medicolegal autopsies may occasionally identify unexpected and rare disorders that have been confused with the sequelae of inflicted injury.     

REPRESENTATION DISPARITIES AND IMPARTIALITY: AN EMPIRICAL ANALYSIS OF PARTY PERCEPTION OF FEAR,PREPARATION, AND SATISFACTION IN DIVORCE MEDIATION WHEN ONLY ONE PARTY HAS COUNSEL

While other authors have regarded both the presence and the absence of attorneys in family law mediation as cause for concern, little attention has been given to the questions raised when one party is represented and the other is pro se. This article presents data on mediating parties' premediation concerns, fears, and feelings of preparedness, as well as their postmediation satisfaction with the mediation process. The mediating parties are grouped based on each couple's representation status, for example, both represented by attorneys, both pro se, or one attorney‐represented party and one pro se party (mixed representation cases). The data show that mixed representation cases are the most likely to report concern, fear, and unpreparedness. Mixed‐representation cases also reported the lowest levels of satisfaction after the mediation. Some implications for mediation practice are discussed, as are suggestions for future research.