The relationship between substance use, drug selling, and lethal violence in 25 juvenile murderers

The goal of the present study was to determine the relationship between substance use, drug selling, and lethal violence in adolescent male homicide offenders and their victims. The study employed a retrospective review of criminal justice databases and medical examiner records for murders committed by 25 adolescent males incarcerated in the Commonwealth of Virginia juvenile correctional centers from February 1992 to July 1996. The perpetrator sample was 84% African American and 16% white. The average age at the time of the offense was 15.0 years (range = 13.0 to 17.7 years). The victims were 84% male, 60% African American and 32% white. The median victim age was 28.0 years (mean = 34.8, range = 17 months to 75 years). The results indicated that 52% of the murders were committed by juveniles with identified involvement in drug selling, and 28% of the murders were drug-related. Toxicology results indicated recent drug or alcohol use in 27% of the victims; while 74% of the perpetrators reported substance use, 35% indicating daily use. Using discriminant analysis, it was possible to accurately classify 86% of the drug-related murders with the variables of recent victim drug use and perpetrator substance use history. The results indicated that adolescent males involved in the sale and distribution of illegal drugs comprised a significant percentage of those incarcerated for murder. Recent victim drug use and perpetrator substance use may be important variables in identifying drug-related juvenile homicides. These results underscore the link between substance use, drug selling, and lethal violence.     

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.     

Postmortem redistribution of morphine and its metabolites

The postmortem redistribution of morphine, morphine-3-glucuronide, morphine-6-glucuronide and total morphine was assessed in 40 heroin-related deaths. In blood taken from subclavian, heart, and femoral regions, concentrations of morphine and its metabolites were similar. While there was a trend for higher concentrations in heart blood, when compared with femoral or subclavian blood, this was not significant. There was also no significant difference in concentrations between admission and autopsy blood in which the postmortem interval was on average 59 h. From our observations, significant postmortem redistribution of morphine and its metabolites seems unlikely.     

Formation of an interfering substance, 3,4-dimethyl-5-phenyl-1,3-oxazolidine, during a pseudoephedrine urinalysis

During fatal aviation accident investigations, biosamples from the victims are submitted to the FAA Civil Aeromedical Institute (CAMI) for drug analysis. In the process of one such analysis by CAMI, an unknown substance was found in a urine sample. Simultaneous screening by thin layer chromatography (TLC) and gas chromatography/FID (GC/FID) suggested the presence of pseudoephedrine. A subsequent routine confirmation analysis of a separate urine aliquot by GC Fourier transform infrared (GC/FTIR) and GC mass spectrometry (GC/MS) indicated that the retention times of the unknown substance matched with those of pseudoephedrine. However, its infrared and mass spectra were different--the -OH and -NH groups were missing, a C-O-C group was present, and the molar mass was 12 atomic mass units (amu) more than that of pseudoephedrine. A subsequent literature search suggested that ephedrine-like amines react with aldehydes to form oxazolidines. Therefore, the 12-amu increase could be accounted for by condensation of pseudoephedrine with formaldehyde. Since this aldehyde is present in various grades of methanol and ethyl acetate, and these solvents were used during the solid-phase extraction, 3,4-dimethyl-5-phenyl-1,3-oxazolidine was synthesized by using (+)-pseudoephedrine HCl and formaldehyde. The analytical findings of the synthesized compound were consistent with those of the unknown interfering substance, confirming that it was the oxazolidine. Aldehyde contaminants in solvents or specimens can transform drugs of interest and may result in misidentification of a compound originally present in specimens. Therefore, chemicals used in analyses should be of the highest available purity, and a multi-analytical approach should be adopted to maintain a high degree of quality assurance.     

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.     

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.     

Detection and correction of a migration anomaly on a 310 genetic analyzer

During STR analysis on the 310 Genetic Analyzer, retarded migration of GS500ROX size standards and alleles in some samples was observed. The contribution of reagents, capillary and performance optimized polymer POP 4 to the observed anomaly was experimentally eliminated. Variation in electrophoresis temperature between 55 degrees C and 65 degrees C did not alter the rate of migration of GX500ROX size standard and sample alleles. An eroded connector for the cathode mounted on the heat plate assembly caused the abnormal migration. Hence, it is important to verify the mobility of all fragments in the size standard for each sample to avoid any erroneous allele calls by the automated data analysis software.     

Loss of heterozygosity detected in a short tandem repeat (STR) locus commonly used for human DNA identification

Short tandem repeat (STR) markers are commonly used in basic genetic research and in human identification testing. Clinically, STRs can be used to study genetic alterations in tumors. A genetic deletion common to many types of cancer is referred to as the loss of heterozygosity (LOH). Numerous examples of LOH in cancer have been described and some have been mapped to areas located in close proximity to markers employed in human identity testing. Despite this fact, LOH has rarely been observed for STR loci commonly employed in forensic testing. Recently, for medico-legal purposes, we were asked to determine whether a tissue biopsy originated from a particular individual. For a reference source we assessed two specimens, one from normal tissue and one from cancerous tissue. When both reference specimens were used to generate DNA profiles, we observed LOH at one STR locus, D13S317. As demonstrated in other cancers only the cancerous biopsy demonstrated LOH. The forensic community should be cognizant of these unusual circumstances because, as identification of human DNA continues to be used more extensively, certain instances will arise in which reference material will not be readily available. In these situations, archived specimens may be employed as a reference source. Clinical specimens such as tissue biopsies should be used with caution if they have not been confirmed to contain normal tissue.     

Suicide by electrocution with low-voltage current

Three cases of suicide by electrocution with low-voltage current were observed in five years (1994-1998) by medical clinical forensic examiners of an Emergency Forensic Unit of the Paris suburb among 2,000 external death examinations. The cases involved one woman, aged 72 and two men, aged 38 and 41. In the last two cases, electric burns were retrieved under bared electric wires, placed on the arms or fingers in order to realize a hand-to-hand electric circuit involving the heart muscle. In the other case, the electric circuit between mouth and foot also involved the heart muscle. Household low-voltage current delivered (220 V in France) had a sufficient strength to induce local muscular paralysis and heart fibrillation. In the three cases, blood samples taken have retrieved very high levels of muscular enzymes (CPK, LDH) correlated to the mechanism of electric death. The rareness of suicide by electrocution and its forensic characteristics are detailed in order to help the clinical forensic examiners, prosecutors, and police officers concerned by such death examinations.