The hypothesis that poisoning by phosphines, arsines and stibines might be the primary cause of sudden infant death syndrome (SIDS) was investigated. Most mattress materials contain phosphorus or antimony compounds as fire retardant additives. Mattress materials in areas affected by the warmth and perspiration of the sleeping infant were found to be naturally infected by the fungus Scopulariopsis brevicaulis which is thought to be capable to generating phospines, arsines and stibines from materials containing phosphorus, arsenic or antimony compounds. These gases may cause anticholinesterase poisoning and cardiac failure in infants, but contributory factors include the prone sleeping position and overwrapping. In England and Wales, the progressive increase in SIDS between 1951 and 1988 seems to be related to increasing use of phosphorus and antimony compounds as fire retardents in cot mattresses.
It is one thing to take part in a training programme-it is another to claim competence! Personal competence can only be satisfactorily demonstrated by first defining performance criteria and then assessing whether these have been achieved. Qualifications, to be meaningful, should reflect competence. The progress in the development of vocational qualifications is presented, together with proposals for future work.
Captagon (fenethylline) has been banned in Saudi Arabia since 1986. Despite this, it remains popular with problem drug users and is in widespread illicit production. Of 667 batches of seized ''Captagon'' tablets subjected to physical and chemical tests, 84% were found to be illicitly-produced fenethylline from a common source, and 16% were found to be fake tablets, consisting of a mixture of quinine and caffeine, also presumed to have a common origin. Fenethylline was synthesised by a modification of the German patented method.
Arson is a serious crime but the cause of an arson fire can be difficult to find. Field portable electronic noses are evaluated in this study for their ability to detect the presence of accelerants in specific areas of a fire scene. Several common household materials are tested, with and without being burned with common accelerants, to determine the readings achieved with the electronic noses. Most samples were found to have detectable amounts of volatile compounds after burning. Some of the matrix materials alone were found to have levels similar to those of the accelerants. A proficiency test designed for accelerant detecting canines was replicated using one of the electronic noses. The detector was found to successfully discriminate between samples containing only matrix and those which also contained accelerants. However, it was not able to alert to the location of a small amount of accelerant spiked onto a pine board. For the extraction and collection of accelerants from fire debris, a portable dynamic headspace sampler is used. Volatile compounds are drawn off the headspace of a sample and deposited in an adsorbent filled tube. The desorbed samples are analyzed by gas chromatography/mass spectrometry. This method has demonstrated ability to concentrate small amounts of a range of volatile accelerants from burned debris. The three field portable instruments have shown to be useful and will continue to be evaluated for their ability to detect and collect accelerants in fire debris.
The effect of ageing and weathering on certain features used to identify shoe polish marks on clothing were investigated; these features included UV/Vis spectra, dye constituents and heat volatile components. Their stability was sufficient for the features to be used to identify shoe polish after ageing and/or weathering.
Toxicological analyses on a putrefied cadaver are sometimes difficult to achieve, because of the absence of blood and/or urine. Drugs present in a decomposing corpse may be identified through analysis of maggots feeding off it. In this study, morphine and codeine were simultaneously identified and assayed in blood and bile of a putrefied cadaver and in the fly larvae of Calliphoridae found on the corpse.
An abortive investigation into an armed robbery is reported, and the need for the preservation of evidence, careful evaluation of the significance of negative results and integrated management of the investigations is described.
Several modifications have been made to a system of simultaneous phenotyping of EAP, EsD, PGM and ADA in bloodstains by isoelectric focusing, which improved the results of the system. An increase in the thickness of the gel improved the resolution of the isozymes' bands, especially PGM and EAP, and diminished the effect of overloading. By increasing the width of the gel it was possible to increase the number of samples applied to the gel. By coating one of the glass plates, used in the preparation of the gels, with a hydrophobic solution, separation of the plate from the gel was greatly facilitated. Finally, the system was found to be very useful as a rapid screening method prior to DNA testing.
The interpretation of human hair comparisons is highly subjective and examiners tend to be cautious when evaluating positive evidence, partly because of a lack of background information relating to the interpretation of the results obtained. The purpose of this paper is to share the authors' experience of examining a large number (118) of samples of Afro-Caribbean hair. The strategy employed provided a rapid response, and only 11 (9.3%) individuals could not be excluded on the basis of hair comparison. It was concluded that not only are comparisons of Afro-Caribbean hairs possible but a significant proportion of individuals can be excluded by such tests.
A simple and efficient method for extracting human genomic DNA from microsamples of blood has been developed. This method used sodium perchlorate, chloroform, polymerised silica gel and a dumbbell-shape tube, instead of proteinase K and phenol. The entire process took less than two hours, and high molecular weight DNA, in high yield and purity, was obtained from a few microlitres of human blood. DNA prepared in this way can be easily digested with restriction endonucleases and has been employed for DNA profiling and the polymerase chain reaction.
Results are presented of amylase tests performed on more than 400 casework swabs using Phadebas tablets. Amylase levels indicative of saliva were obtained from 25% of the penile swabs tested, 32% of the vaginal swabs and 50% of the breast swabs. The longest time interval between the offence and sampling when such levels were detected was 16 hours for penile swabs, 55 hours for vaginal swabs and 30 hours for breast swabs.
Stains of 26 different shoe polish types on white cotton fabric have been analysed. The heat volatile components, dyes and pigments of the polishes were compared. Differentiation between certain polish types of the same colour is possible using a combination of these tests.
In experiments on different polymers, It was demonstrated that swelling and polishing rates, and thermal properties were different for undeformed and deformed regions of the polymer. These processes can therefore be used for the restoration of erased numbers.
A polydimethylsiloxane (PDMS) liquid is used as a lubricant by many condom manufacturers. Because the use of condoms in sex crimes is likely to increase, a protocol was developed that could extract PDMS and the spermicide nonoxynol-9 from evidence items and separately identify them by Fourier transform infrared spectroscopy. Additionally, at least some discrimination was provided by microscopically identifying insoluble lubricants such as corn starch, lycopodium, silica, and talc which are added to some brands. Desorption chemical ionization mass spectrometry was used to compare the PDMS used by different manufacturers and to detect as little as 20 ng. The protocol was successfully used in two actual cases, one in which the assailant wore a lubricated condom, and a second in which he did not, but claimed to have done so.
The evaluation of a commercially available, faecal occult blood test to determine the species of origin of unknown stains is described. This test was simple to perform, requires a minimum amount of equipment and produced results that were easy to interpret. The HemeSelect test was found to be at least two orders of magnitude more sensitive than a precipitin test and would be the test of choice for small or aged stains.
