Effect that the relative abundance of copper oxide and zinc oxide corrosion has on the visualization of fingerprints formed from fingerprint sweat corrosion of brass

From an examination of the fingerprint sweat corrosion of 40 different individuals on α phase brass, we show that an increase in visualization can be achieved by applying a negative potential to the brass followed by the introduction of a conducting powder. Previously, this technique has been demonstrated only for a positive applied potential and a corrosion product that was dominated by p-type copper (I) oxide. X-ray photoelectron and Auger electron spectroscopic analyses of the surface of the corroded brass show that an increase in visualization with a negative applied potential corresponds with an increase in the concentration of n-type zinc oxide relative to p-type copper (I) oxide with the Cu:Zn ratio <0.8:1. Work function conditions for the formation of an n-type zinc oxide/brass rectifying Schottky barrier are fulfilled.     

Visualization of latent fingermark corrosion of brass, climatic influence in a comparison between the U.K. and Iraq

Through a comparison of fingermark sweat corrosion of α phase brass in both the U.K. and Iraq, we show how samples from Iraq have improved fingermark corrosion over U.K. samples that require no additional enhancement prior to visualization. Over 50% of Iraqi samples produced fingermark corrosion with full ridge detail compared with 0% from the U.K. X-ray photoelectron spectroscopy analysis of the fingermark corrosion products showed that Iraqi samples exhibit more dezincification with the Zn:Cu ratio averaging 1:1.82 compared with 1:3.07 for U.K. samples. Auger spectroscopy showed the presence of both zinc oxide and copper (I) oxide. No copper (II) was observed on the surface of the corroded brass. Opportunities to exploit the optical properties of these thin film oxides to enhance the visualization of fingermark corrosion are considered, and the potential to use fingermark corrosion of metal as a means of visualizing fingerprints in war zones is discussed.     

The Relationship Between Deprivation and Forensic Material Recovered from Stolen Vehicles: Is it Affected by Vehicle Condition and Tidiness?

Previous research has shown that as crime scene location deprivation increases (lower socioeconomic status), the recovery of forensic material, principally DNA and fingerprints, also increases. However, this increase does not result in more crimes being solved by forensic means. In this study, we analyze stolen vehicle data and find a statistically significant positive association between deprivation and the amount of forensic material that matched either the victim or an associate of the victim on a criminal database. The nature of this association was investigated further by inspecting recovered stolen vehicles to establish whether the condition of a stolen vehicle and the tidiness of its interior influenced the recovery of forensic material that was attributed to the victim or an associate. Contradictory results suggest that other factors may contribute to understanding the association between the recovery of victim- or associate-attributable forensic material and crime scene location deprivation.     

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.     

Panel on the Economic and Political Consequences of Chernobyl'

This article summarizes a discussion by a panel of leading experts on Soviet energy analyzing the consequences of the accident at the Chernobyl' nuclear plant in the Ukraine on April 26, 1986.

The near-term economic costs associated with clean-up, relocation, and compensating for losses to electricity supplies are significant but manageable. The longer-term effects will focus on likely modifications in Soviet strategies for the nuclear industry, which may shift emphasis back towards conventional fuels and conservation.

The political consequences were managed fairly well by the leadership. Consistent with Secretary Gorbachev's policy of glasnost' (openness) more information has been available on this event than was the case in previous analogous situations. Journal of Economic Literature, Classification Numbers: 027, 124, 723.     

Gorbachev's Economic Reform: A Soviet Economy Roundtable

The proceedings of a panel of American specialists devoted to the recent economic reform are summarized. The panelists noted that the most substantial changes to date have accompanied efforts to restructure the decisionmaking hierarchy—in particular, a recentralization of authority through the creation of biuros and state committees and legislation on individual economic activity. Changes in the systems of economic planning and incentives, on the other hand, have been minor, suggesting a continuing debate over the extent to which price reform and various economic incentives should be implemented. Journal of Economic Literature, Classification Numbers: 052, 113, 124.     

‘Look into my eyes’: can an instruction to maintain eye contact facilitate lie detection?

Abstract

Traditionally, research on offender profiling has investigated the relationships between offender behaviour and offender characteristics. However, evidence about offender behaviour is not the only evidence available at a crime scene. This study extends previous collaborative research between forensic scientists and psychologists (e.g. Bond & Sheridan, Journal of Forensic Science, 52, 1122–1128, 2007) to investigate how forensic science can assist in the psychological process of offender profiling. Specifically, the potential utility of footwear impression evidence in the task of offender profiling is investigated. Using 155 domestic burglaries, the consistency and homology assumptions underlying offender profiling were tested. Evidence supportive of both assumptions is reported. A multiple regression analysis identified significant relationships between cost of footwear and employment status, age of offender, and the relative deprivation of his/her residence.     

Introduction to issue number two

“Groen Links (Green Left) is Holland's new, radical, green party, which occupies a space to the left of the Social Democrats. It has been formed through the unification of four smaller left wing parties, and as its name makes clear it involves a conscious attempt at a fusion of red and green politics.”