Population genetics of nine STR loci in two populations from Brazil

The Short Tandem Repeats (STRs) D3S1358, HUMvWA31/A, HUMFIBRA/FGA, D8S 1179, D2S11, D18S51, D5S818, D13S317, and D7S820 were studied in two Brazilian populations (from Amazonia and S. Paulo) using the "AmpF1 STR Profiler Plus PCR Amplification Kit." The nine loci showed a combined discrimination power greater than 0.9999999999 and a chance of exclusion of 0.9999.     

Population genetics of the D1S1656, D12S391, and D18S535 loci in Asturias (North Spain)

Allele and genotype frequencies for three recently described short tandem repeat loci D1S1656, D12S391, and D18S535 were determined in a population sample from Asturias (North Spain). The loci were amplified using a fluorescence based PCR method and were typed automatically. No deviation from Hardy-Weinberg expectations were observed. The three loci proved to be highly discriminating and the allele frequencies observed are similar to those of the other European populations that have been typed for these loci to date.     

Obtaining fingerprints from mummified fingers: a method for tissue rehydration adapted from the archeological literature

Our laboratory was asked to help with the rehydration of mummified human fingertips that had been removed from a recently deceased, unidentified female. Using a solution that was found in the archeological literature, we were able to successfully rehydrate dermal tissues to the extent that fingerprints could be taken. We believe that this solution, which until now has not been described in the forensic literature, is effective, affordable, and relatively easy to produce and use.     

DNA typing of samples for polymarker, DQA1, and nine STR loci from a human body exhumed after 27 years

A body was exhumed from the ground after 27 years. Samples of femur bone, tooth, and a fingernail were collected and successfully subjected to DNA extraction, quantitation, amplification, and subsequently typed for DQA1, polymarker, and nine STR loci. All three types of samples were typed for D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S17, D7S820, and amelogenin using ABI Prism 377 DNA sequencer.     

The Frye hearing in Florida: an attempt to exclude scientific evidence

State Supreme Courts require a minimum threshold of reliability and acceptance in the scientific community for all medical and similar evidence to be admitted at trial. In Florida and some other states, the courts adhere to what is known as the Frye standard, whereas in most states and in Federal Courts, it is the so-called Daubert standard. The jurisdiction of the present case is Hillsborough County (Tampa), Florida. Forensic pathologists seldom, if ever, are requested to participate in such hearings, unlike their toxicological and basic science colleagues who are more involved in research methodology and technical procedures. The burden is on the proponent of the evidence to prove the general acceptance of both the underlying scientific principle of the test and procedures used to apply that principle to the facts of the case at hand. The trial judge has the sole discretion to determine this question and general acceptance must be established by a preponderance of the evidence. The authors describe in detail a hearing in a case in which they were all involved. One author (WQS) had researched and documented the original scientific methodology in the literature. The situation involved a car and tractor trailer crash with the two occupants of the car dying of multiple trauma, whereas the truck driver was not injured. Autopsy of the auto driver revealed multiple injuries with exsanguination, and only vitreous humor and liver tissue, but not blood, were tested for ethyl alcohol. The estate of the driver of the automobile brought suit against the owner of the trucking company for wrongful death. The plaintiff requested a Frye hearing to question the reliability of testing other body specimens to translate to probable blood alcohol level. The testimony, submitted documents, and eventual decision by the judge are discussed.     

Unusual cases of suicide among health care workers

We describe three unusual cases of suicide committed by health care workers. The aim of this paper was to analyze and evaluate the evidence of general diagnostic elements of poisoning in these cases.     

Evaluation of 1,2-indanedione and 5,6-dimethoxy-1,2-indanedione for the detection of latent fingerprints on porous surfaces

The ability of 1,2-indanedione and 5,6-dimethoxy-1,2-indanedione to detect latent prints on porous surfaces, as compared to DFO and ninhydrin, has been evaluated. Comparisons of prints developed under various conditions determined the optimum development conditions for the new reagents. The indanediones tested were found to have lower detection limits for glycine. The carrier solvent used was found to affect the quality of the prints developed. In Arklone, the new reagents developed prints that displayed superior luminescence to those developed with DFO. In HFE 7100, 1,2-indanedione and 5,6-dimethoxy-1,2-indanedione gave superior luminescence to DFO after zinc salt treatment and cooling with liquid nitrogen, both of which improve the luminescence of prints developed with 1,2-indanediones. 1,2-Indanediones could offer less expensive but effective alternatives to DFO. With further optimization, the new reagents may supersede DFO as the method of choice for the detection of latent fingerprints on porous surfaces.     

Comparison of patterns of decomposition in a hanging carcass and a carcass in contact with soil in a xerophytic habitat on the Island of Oahu, Hawaii

Decomposition studies were conducted to determine differences in rates and patterns of decomposition of carcasses hanging and exposed on the surface of the soil. These studies were conducted between 17 October and 17 December 1997 inside of Diamond Head Crater on the island of Oahu, Hawaii. The animal model was the domestic pig. Sus scrofa. The rate of biomass removal from the hanging carcass was significantly slower than that observed for the control carcass during the bloat and decay stages of decomposition. Internal temperatures for the control carcass were elevated above the ambient air temperatures during the earlier stages of decomposition (bloated and decay), while those recorded for the hanging carcass approximated the ambient air temperatures. There was a greater diversity of arthropod species recorded and numbers of individuals observed were higher for the control carcass. A significant site of arthropod activity was observed on the surface of the soil immediately under the hanging carcass and this became the primary site of arthropod activity as decomposition progressed.     

A new visibly-excited fluorescent component in latent fingerprint residue induced by gaseous electrical discharge

A technique that exposes fingerprint residue to a gaseous electrical discharge in nitrogen followed by treatment with ammonium hydrogen carbonate vapors to produce fluorescence is investigated. Particular attention is made to fluorescence observed via laser illumination at 514 nm. Insight into the nature of the fluorescent components is achieved through the use of thin-layer chromatography (TLC) of fingerprint residue. Results reported indicate the fluorescence observed is from previously non-fluorescent fractions of the fingerprint residue, and TLC results point towards lipid derivatives as a possible source of the fluorescence.