Corneal‐Smart Phone: A novel method to intelligently estimate postmortem interval

The changes of postmortem corneal opacity are often used to roughly estimate the postmortem interval (PMI) in forensic practice. The difficulty associated with this time estimate is the lack of objective means to rapidly quantify postmortem corneal changes in crime scenes. This study constructed a data analysis model of PMI estimation and implemented an intelligent analysis system for examining the sequential changes of postmortem corneal digital images, named Corneal‐Smart Phone, which can be used to quickly estimate PMI. The smart phone was used in combination with an attachment device that provided a darkroom environment and a steady light source to capture postmortem corneal images. By segmenting the corneal pupil region images, six color features, Red (R), Green (G), Blue (B), Hue (H), Saturation (S), Brightness (V) and four texture features Contrast (CON), Correlation (COR), Angular Second Moment (ASM), and Homogeneity (HOM), were extracted and correlated with PMI model. The results indicated that CON had the highest correlation with PMI (R² = 0.983). No intra/intersubject variation in CON values were observed (p > 0.05). With the increase in ambient temperature or the decrease in humidity, the CON values were increased. PMI prediction error was <3 h within 36 h postmortem and extended to about 6–8 h after 36 h postmortem. The correct classification rate of the blind test samples was 82%. Our study provides a method that combines postmortem corneal image acquisition and digital image analysis to enable users to quickly obtain PMI estimation.     

A case study on the application of isotope ratio mass spectrometry (IRMS) in determining the provenance of a rock used in an alleged nickel switching incident

The application of isotope ratio mass spectrometry (IRMS) in forensic science to establish the provenance of a range of questioned substances including soils, drugs, explosives, currency, ivory and rhino horn has been widely documented. The present study wishes to highlight the applicability of IRMS and specifically stable carbon IRMS in determining the provenance of a carbonate rock that was switched for nickel metal exported from South Africa to Israel. The technique employed effectively argued against a South African origin for the rock whilst simultaneously supporting an Israeli origin, enabling investigators to focus their attention accordingly. The study represents the first documented instance known to the authors where IRMS has been employed in the forensic geo-location of a rock.     

Rand Daily Mail: die dood in perspektief

SUMMARY

The closure of the Rand Daily Mail on April 30, 1985 focused the attention of South Africans on the state of the South African press. This (mainly white) press is examined in the article. It is found that if one uses Merill & Lowenstein's EPS curve of stages of media development in South Africa, the white press is already in the Modern phase, with saturated mass publications, decreasing readership of the mass press and an increasing commitment to specialization and diversification. The black publications are in the Transitional phase, moving from the Elite phase to the Popular phase, with a great potential for mass publications due mainly to increasing literacy and rising levels of income. Readership among Blacks has increased by some 250 per cent between 1962 and 1977. Conclusions drawn from these findings seem to indicate that the Rand Daily Mail had not taken adequate account of the realities of the media market and had positioned itself in a no-man's-land between a sophisticated white market and a developing black one. It had proved itself second best against both its main white and black rivals, namely Citizen and Sowetan. It is recommended that, due to the press's economic difficulties and the need for a diversity of views in a reforming constitutional system on the road to greater democracy, government subsidization of the press be considered seriously as an option for the future.     

Photo identification: facial metrical and morphological features in South African males

Personal identification of individuals is very important in forensic sciences. Facial identification is becoming even more relevant with increasing crime rates, problems with access control and terrorist attacks. To make facial identification more accurate, an in depth knowledge of the common and rare facial characteristics seen in various populations is needed. This will be advantageous when comparing facial photographs. Currently very little data is available on the facial variation of South Africans. Therefore the aim of this study was to analyse the facial features of a group of South African Bantu-speaking men, to determine the common and rare facial features seen in the group. Facial photographs were taken for 200 volunteers from the Pretoria Police College, in the norma frontalis position. The subjects were between 20 and 40 years of age, with no facial deformities. Thirteen measurements were taken directly from the photographs and used in 12 indices. Eight morphological features were also analysed on each face. Each feature was divided into different categories, which described variants of that feature. The metrical and morphological data were then used to create various combinations of facial characteristics that described different regions of the face. The frequency of occurrence of these combinations was calculated for the study population. The most common features were oval or inverted trapezoid facial shapes, intermediate size noses with a down-turned septum tilt and intermediate size mouths with a flat V-shaped upper lip notch (cupid's bow). The eyes were mostly situated closely together. Some of the rare or absent features included round or square facial shapes and narrow noses with an upturned septum tilt. Matching these rare features on facial photographs will be useful during cases of disputed identification.