Touch DNA: The effect of the deposition pressure on the quality of latent fingermarks and STR profiles.

Latent fingermarks (FMs) present unique, and sometimes the only, evidence found at a crime scene. Several factors affect their quality, including deposition pressure (DP). Its effect on FM size and quality, and on STR amplification success rate, is an emerging area of interest in forensic science. This study examined 540 FM samples, each consisting of index, middle and ring fingers, deposited by 30 donors on glass, polythene (PE) and paper under a range of weights from 0.1 to 10 kg. Both length and width of FMs increased with the increasing DP. FMs deposited under lower (≤0.5 kg) DPs varied in size (p < 0.01), while those deposited at higher (≥3 kg) DPs were more consistent. FM quality on glass and PE, as determined by the AFIS minutiae count and by a fingerprint examiner on a scale from 0 to 4, improved with the increasing DP, but it deteriorated on PE at DP of 10 kg. FM quality on paper continued to improve from DP of 1 kg up to the maximum DP of 10 kg. The effect DP has on the efficacy of DNA profiling from latent FMs was significant as shown by an increase in the DNA amount recovered, the number of amplified loci per FM sample, and the number of forensically useful DNA profiles (defined here as those with ≥8 full STR loci detected) as DP increased. This effect was most pronounced with PE (R = 0.98) and paper (R = 0.96). Altogether, the success rate of DNA profiling varied from 16.3% in FMs deposited on paper to 21.2% and 22.5% of those on PE and glass. The highest number of useful DNA profiles was obtained from glass under DP of 10 kg. Forensically useful FMs obtained at low (≤1 kg) DP from all three substrates significantly outnumbered that of STR profiles, while an opposite, though less pronounced trend, was observed at high (≥3 kg) DP on PE and paper. Application of the simple device for collecting of FMs under controlled pressure designed for this study, and the palm-up mode of FM deposition as described, allowed us to eliminate the undesirable effect of the hand self-weight and to objectively assess the actual effect of increasing DP on FM size and quality, as well as on the efficacy of DNA profiling.

Selective recognition of fluoride salts by vasarenes: a key role of a self-assembled in situ dimeric entity via an exceptionally short [O-H-O](-) H-bond.

A self-assembled supramolecular dimeric entity via an exceptionally short (2.404 Å) and strong (22.9 kcal mol(-1)) [O-H-O](-) hydrogen bond is the key to the special reactivity of vasarenes with fluoride salts. Vasarene is a self-assembled, vase-shaped compound, obtained by the reaction between ninhydrin and phloroglucinol. Analogous compounds are prepared by replacing the phloroglucinol with other polyhydroxy aromatics. Vasarenes show special affinity towards compounds of the type M(+)F(-), where M being a large monovalent cation, producing ion-pair-vasarene adducts. The first step in the proposed mechanism is the dissociation of the M(+)F(-) salt releasing F(-) to the solution, which may provide an explanation as to why only MF salts, which include large monovalent cations, undergo this reaction. From a practical point of view, the ease of their preparation and their special affinity towards fluoride salts make vasarenes potential means for salt separation. The readily formed dimeric structure with the very short [O-H-O](-) negative charge-assisted H-bond (-CAHB) can also be further used as a model in theoretical studies of such systems and understanding their role in biological processes.

Proactive forensic science: a novel class of cathinone precursors.

Nine new derivatives of cathinone, which are not covered by present illicit-drug laws in Israel and other countries have been synthesized and characterized. Unlike most of the modified cathinones on the illicit drug market, these compounds are obtained by modifying the carbonyl group of the parent compound. The new group contains cyclic ketals and thioketals, oximes and hydrazone, of cathinone and of cathinone phthalimide. Cathinone is readily regenerated from the new derivatives by acid hydrolysis. Consequently, they can be regarded as potential pro-drugs, and their inclusion in the illicit-drugs bylaws should be considered.

Substituted naphthoquinones as novel amino acid sensitive reagents for the detection of latent fingermarks on paper surfaces.

In this paper, we present our preliminary studies into naphthoquinones as novel reagents for the detection of latent fingermarks on paper. Latent fingermarks deposited on paper substrates were treated with solutions of selected naphthoquinones in ethyl acetate/HFE-7100, with subsequent heating. The selected compounds were 1,4-dihydroxy-2-naphthoic acid, 1,2-naphthoquinone-4-sulfonate, 2-methoxy-1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone. All of the tested compounds yielded purple-brown visible fingermarks, which also exhibited photoluminescence when illuminated with a high intensity filtered light source at 555 nm and viewed through red goggles. Indirect heat using an oven at 150°C for 1h was found to be superior to direct heat with an iron, which while providing faster development lead to increased levels of background colouration. Luminescence spectrophotometry revealed differences in photoluminescence characteristics for fingermarks developed with the different naphthoquinones, with excitation over the range 530-590 nm. Luminescence spectrophotometry of developed lysine, glycine and serine spots on paper was used to confirm that the naphthoquinones were reacting with amino acids in the latent fingermark.

Detection of firearm imprints on the hands of suspects: effectiveness of PDT reaction.

Pyridyldiphenyl triazine (PDT) and three of its analogues were compared as practical reagents for visualizing unseen impressions left on the hands of a person who has held a firearm. The parent compound, PDT, gave the best results using intensity and clarity as measuring criteria. The effectiveness of the PDT reaction was then studied on 147 volunteers who had held firearms in their hands. Identifiable impressions of the metallic parts of the weapons were developed on the hands of 103 volunteers (70%). Results with females were slightly higher than with males, however, the difference was possibly statistically insignificant, and needs further study. Ferroprint and Ferrotrace, 5 commercial preparations that are based on the PDT reaction, have become a part of the professional equipment of every crime scene technician in Israel.

Chemical development of latent fingerprints: 1,2-indanedione has come of age.

The performance of 1,2-indanedione as a latent fingerprint reagent on some types of paper was found to exceed that of DFO, the leading fluorogenic fingerprint reagent. It even exceeds the performance of the sequence, DFO, followed by ninhydrin. No new prints could be observed when ninhydrin was applied after indanedione. On a large number of actual exhibits (used checks) indanedione developed 46% more identifiable prints than the sequence DFO-ninhydrin. A standard procedure for fingerprint development by indanedione is proposed. Best results are obtained with a 0.2% indanedione solution in HFE7100 solvent containing 7% ethyl acetate, but no acetic acid. It can be recommended to start using 1,2-indanedione, which is already commercially available, in actual fingerprint casework.

Immunochemical approaches for purification and detection of TNT traces by antibodies entrapped in a sol-gel matrix.

A highly sensitive immunochemical method for immunoaffinity purification (IAP) and detection of trace amounts of TNT was developed on the basis of antibodies (Abs) in a ceramic matrix (sol-gel). The study resulted in: (i) a highly sensitive and reproducible TNT ELISA (I50 and I20 values of 0.4 +/- 0.09 ppb and 0.12 +/- 0.03 ppb, respectively; n = 12), which is highly specific to TNT; and (ii) successful entrapment of the Abs that bound free analyte from solution. Binding was found to be highly reproducible, dose dependent, and only slightly (1.2-1.8-fold) lower than that in solution. The entrapped Abs did not leach from the matrix and were tolerant of absolute ethanol, acetone, and acetonitrile. Bound analytes could be easily eluted from the sol-gel matrix at high recoveries. The sol-gel-based IAP method described above introduces a simple one-step procedure that has a high potential to serve as a suitable and convenient immunochromatographic device for cleanup and concentration of TNT from "real field" samples in a manner that complies with both chemical and immunochemical residue analysis methods.

Fingerprint forgery--a survey.

The article describes and analyzes the international survey of fingerprint and laboratory personnel about fingerprint forgery, conducted in four countries during the years 1998 through 1999. The awareness and the attitude of the professionals to the problem of fingerprint forgery was tested.

Chemical development of latent fingerprints: computational design of ninhydrin analogues.

The design of chemical compounds for development of latent fingerprints is explored computationally. Our main findings are: (a) We show why past attempts to improve the widely used ninhydrin gave relatively small improvements (referring to color only). The optical transition is connected with a "transition core" and therefore is influenced little by substitution on the aromatic rings. (b) We propose new analogues of ninhydrin with a significant potential such as thiono derivatives.

Reagents for the chemical development of latent fingerprints: scope and limitations of benzo[f]ninhydrin in comparison to ninhydrin.

Benzo[f]ninhydrin was compared to ninhydrin for fingerprint development on paper. Overall, the performance of ninhydrin on exhibits was slightly better than that of benzo[f]ninhydrin. The significant advantages of the benzo[f]ninhydrin over ninhydrin were the much stronger fluorescence it gave after treatment with zinc salts and a slightly quicker reaction under ambient conditions. This fluorescence is, however, similar to that obtained with other reagents, such as DFO or ninhydrin analogs. These advantages apparently are not sufficient to justify regular usage of benzo[f]ninhydrin, especially when one considers its low solubility and high cost.

Marine taphonomy: adipocere formation in a series of bodies recovered from a single shipwreck.

Taphonomy of marine environments has been studied mostly from individual cases. The formation of adipocere, or "grave-wax," is an important indicator of the postmortem interval. In the present paper, the conditions and the timing of adipoceric formation are observed in a series of 15 cadavers recovered at different times, over a period of 433 days, from the same contained environment. Initial foci of adipocere on the subcutaneous tissue of the cadavers were detected as early as 38 days from the time of immersion in cold (10-12 degrees C) sea water. The discrepancies between our findings and previous reports on the correlation between time since death and decomposition stages in marine environments are discussed.

Visualization of sebaceous fingerprints on fired cartridge cases: a laboratory study.

The visualization and endurance of fingerprints on cartridge cases after the firing process have been examined. Cartridges of M16, AK-47 (Kalashnikov) and Parabellum have been tested. Despite difficulties in visualizing these fingerprints, it was found that in some cartridge cases under laboratory conditions--for instance, on M16 brass cartridges--substantial parts of the fingerprints remain intact after shooting. The careful use of illumination after metal vapor deposition enabled visualization. Different possible mechanisms responsible for the partial destruction of the fingerprints are discussed.

Short UV luminescence for forensic applications: design of a real-time observation system for detection of latent fingerprints and body fluids.

An assembly that allows a pseudo real-time (one second delay) observation of latent fingerprints by their short ultraviolet luminescence was designed. It is composed of a mercury-xenon lamp and a CCD camera, both water-cooled and computer-controlled. The system is used to study the behaviour of latent fingerprints and stains of body fluids such as blood, semen and saliva under short-UV illumination.

Nitric oxide synthase inhibitors protect rat retina against ischemic injury.

Elevation of the ocular pressure in the anterior chamber of the rat eye caused major ischemic damage, manifested as changes in retinal morphology. The two most affected structures were the inner plexiform layer, which decreased in thickness by 90%, and the number of ganglion cells, which decreased by 80%. Pretreatment of the animals with N omega-nitro-L-arginine, a nitric oxide (NOS) inhibitor, almost completely abolished the ischemic damage. Administration of aminoguanidine, a NOS inhibitor selective for the inducible enzyme, partially abolished the ischemic damage. Moreover, administration of the NOS inhibitors 1 h after ischemia, also protected the retina from damage, suggesting that similarly acting drugs could be used clinically to limit ischemic injury in humans. We conclude that NOS, and therefore NO, may be involved in the mechanism of ischemic injury to the retina.

Utility of postmortem computed tomography in trauma victims.

A possible way to circumvent the continuing decline in the number of autopsies is to perform computed tomography after death. The present study compares the pathologic findings of postmortem CT tomography (PMCT) in trauma fatalities with those disclosed upon conventional forensic autopsy. Within 6 hours of death, the bodies of 25 trauma victims underwent total body CT scanning, all with permission of the relatives, followed by conventional autopsy in 13 cases under court order. The pathologist and roentgenologist were unaware of each other's findings. The pathologic findings of PMCT plus conventional autopsy provided more information than either examination alone. Of the total 127 pathologic findings, 44.9% were diagnosed by both conventional autopsy and PMCT, 29.9% were not revealed by PMCT, whereas conventional autopsy missed 25.2%, and PMCT detected more bone injuries than did autopsy, whereas the latter was superior to PMCT in discovering soft-tissue pathologic states. In all, PMCT revealed 70.5% and autopsy 74.8% of the pathologic states. Although PMCT was not more effective than conventional autopsy in exposing pathologic entities, it increased the yield of findings when combined with conventional autopsy. Where conventional autopsy is unattainable, PMCT may be effective in shedding light on the pathologic state and mechanism of death in trauma fatalities.

Detection of dry body fluids by inherent short wavelength UV luminescence: preliminary results.

Dry stains of blood, semen and saliva invisible to the naked eye could be detected by their inherent short wavelength UV luminescence. The source was a frequency quadrupled Nd:YAG laser, emitting at 266 nm. A plausible explanation for this phenomenon as due to the presence of amino acids in these secretions is presented.

Reagents for the chemical development of latent fingerprints: synthesis and properties of some ninhydrin analogues.

In an attempt to design new reagents for the chemical development of latent fingerprints, a number of ninhydrin analogues were synthesized and their reactions with latent fingerprints on paper were studied. The ring-fused and substituted ninhydrins developed latent fingerprints with a sensitivity similar to that of ninhydrin. The most promising of the group was 2,2-dihydroxybenz[f]indane-1,3-dione, which developed latent fingerprints as dark green images with excellent resolution.

Chemical reagents for the development of latent fingerprints. III: Visualization of latent fingerprints by fluorescent reagents in vapor phase.

The use of certain fluorescing vapor-phase chemicals for the development of latent fingerprints is described. Some advantages of these chemicals over other methods that use fluorescers are discussed.