The transfer of petrol on to clothing and shoes while pouring petrol around a room

This study was aimed at measuring the approximate amount of petrol transferred on to the clothing and shoes of a person during the action of pouring petrol around a room. Two different heights of pouring and two different types of floor surface (carpet and concrete) were investigated. Results show that for all the combinations examined petrol was always transferred to the shoes and often transferred to the upper and lower clothing. This information illustrates the necessity of analysing the clothing and particularly the shoes of any suspected arsonists for the presence of hydrocarbon fuels.     

The interpretation of shoeprint comparison class correspondences

The underlying principles involved in the interpretation of shoeprint comparisons have become a topical subject due to criticisms in the 2009 National Academy of Science (NAS) report on forensic sciences [1]. Difficulties in the application and understanding of these principles were also highlighted in a recent court ruling [2–5]. We report here a survey that may inform some aspects of this interpretation and discuss the implications of findings from this survey in the light of that court ruling and more importantly the NAS report.Five hundred shoeprints taken from student volunteers in Auckland, New Zealand were compared against each other for the presence of any pattern correspondences. Comparisons were undertaken of the full outsole and of smaller portions of the more common patterns.Of the 500 shoe impressions collected 488 (97.6%) were ultimately represented only once in the survey. The greatest number of corresponding patterns was for the most common brand of shoe (Converse Chuck Taylor All Star) and occurred in 3 of 500 observations. No instances of an imitation brand matching the authentic brand were found. Smaller sections of the common patterns showed a greater number of corresponding prints. However, the greatest number of matching partial patterns was again for the most common brand of shoe (Converse Chuck Taylor All Star) and occurred in 29 of 500 observations.We conclude that pattern match alone is of considerable evidential value even when the print is partial.     

An investigation into the presence of petrol on the clothing and shoes of members of the public

First, the clothing and shoes from 29 participants who had recently filled their vehicles with petrol were analysed for any traces of petrol. No traces of petrol were found on any of these items. Secondly, the clothing and shoes from 17 participants who had recently used a petrol-powered lawn mower were also analysed for petrol. Petrol was detected on two pairs of shoes from different participants. Components of petrol were detected on a set of clothing from a third participant, however, there were insufficient components present in this sample to confirm the presence of petrol. No traces of petrol were found on the items from the remaining 14 participants. Thirdly, the clothing from a forecourt attendant, a mechanic and a professional lawn mower were analysed at the end of a number of shifts. Petrol was detected on the upper and lower clothing from the forecourt attendant at the end of one shift. No petrol residues were found on the forecourt attendant after a second shift, or on the mechanic's clothing after two separate shifts or on the professional lawn mower's clothing after three separate shifts. These results can be used to assist the forensic analyst in assessing the chance of finding traces of petrol on clothing and shoes after the wearer has performed common activities that involve petrol.     

The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples

In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene.     

Institutional constraints on cabinet formation: Veto points and party system dynamics

Research on government formation in parliamentary democracies has presented contradicting evidence on the role of political veto institutions and parliamentary polarization on the formation of cabinet types. Institutional rules may either provide significant leeway for political parties or seriously constrain them when forming sustainable coalitions. In contrast to previous studies we argue that the effect of political institutions is conditional on the degree of polarization in parliament. We test our hypotheses using original data on 842 cabinet formations in 33 advanced democracies between 1945–2018. In line with previous research, we find that the institutional rules have a pronounced effect on the type of cabinet formed, but that institutional rules moderate the effect of party system polarization. Thus, our findings provide important new insights on cabinet formation which are particularly relevant for today's increasingly polarized parliaments.