Transfer of Fibres onto Knife Blades in Stabbing Events: Distribution and Determination of the Stabbing Sequence

Knives are among the weapons most frequently involved in criminal cases.They represent the most encountered category of weapons in Swiss homicide cases(completed and attempted homicides considered)and are also frequently employed in assault cases,notably bodily injuries.Whenever a knife is involved in a stabbing event,DNA and fingerprints may be sought.When garments are damaged,fibres can also be investigated.Fibres from the victim's garments might transfer onto the blade of the knife used in the assault and can thus provide useful infbnnation to determine whether a particular weapon could have be used to stab the victim.This study simulates vertical stabbings into garments with the use of a special holding device.Different types ofknives and blades straight or serrated were used as weapons.Two garments presenting different shedding capacities and garment structures were also considered for the simulations.The distribution of fibres transferred onto the blade(number and position)was recorded for each simulation performed.Sequences of stabbings into the two garments were also carried out to assess whether the order of the stabs could be determined.Several parameters were considered,notably the distribution of fibres transferred onto the blade.The transfer of fibres inside the stab damage ballistic soap was used in this study and on the area near the second damage was also investigated.This study provides new insight into the interpretation of fibres transferred onto knives after a single stab or a sequence of stabbings and into determining the stabbing sequence.Finally,the study brings some guidelines for the search and recovery of fibres on the crime scene and on the blades ofknives.

Cloning and characterization of cholesteryl ester transfer protein isolated from the tree shrew

Objective To obtain the nucleotide sequence and deduced amino acid sequence of cholesteryl ester transfer protein (CETP) cDNA from the tree shrew (Tupaia glis).Methods The cDNA sequence of the tree shrew CETP was obtained by utilizing the technique of switching mechanism at 5' end of RNA transcript (SMART) and rapid amplification of cDNA end (RACE) from the first strand of the cDNA. The amino acid sequence of CETP was deduced from the cDNA sequence and its primary and secondary structures were predicted.Results The sequence of CETP cDNA from tree shrew (GenBank accession number AF334033) covers 1636 bp, including 178 bp at the 3' end of the untranslated region and a 1458 bp fragment in a coding region, which provides the complete sequence of mature tree shrew CETP, although not the initiator methionine. The first 24 bp encodes a partial signal peptide. The mature protein consists of 477 amino acids and is longer than the human version by one amino acid (Gly318). Comparing this amino acid sequence with those of other animals' CETPs, the identity between tree shrew and human and rabbit CETP is 88% and 82%, respectively. The protein is extremely hydrophobic as it contains many hydrophobic residues, especially at the C-terminal, consistent with its function in the transfer of neutral lipids. The amino acid residues concerning with binding and transferring neutral lipids are highly conserved. There is a deletion of an N-linked glycosylation site at Asn342 in the tree shrew CETP protein that may participate in the removal of peripheral cholesterol and cholesteryl ester by increasing its activity of transferring cholesteryl ester.Conclusion The possible glycosylation in the tree shrew CETP may be involved in the molecular mechanism of its insusceptibility to atherosclerosis.