The Distribution of Household Property Crimes

Previous studies have established that repeat victimizations occur more frequently than would be expected if households within a particular area were victimized randomly. This implies that characteristics of the household affect the victimization rate. Even controlling for these characteristics, we find that a Poisson model does not capture the distribution of victimizations because repeat victimizations are more concentrated than it would indicate. This leads us to adopt the negative binomial generalization of the Poisson model. Our analysis uses sociodemographic attributes of the household and community-level characteristics to predict victimizations, with the victimization data being the observed number of property crime victimizations from the 1992 British Crime Survey. The negative binomial generalization is found to be highly statistically significant and the crime concentration it implies becomes much more marked as the predicted number of victimizations increases.     

Detection of bullet residue in bone using proton-induced X-ray emission (PIXE) analysis

External beam proton-induced X-ray emission (PIXE) analysis has been used to verify the presence of lead in the finger bone of a murder victim. The deceased, who had been buried several years, was known to have suffered a bullet wound to his right hand several years before death. X-ray radiographs of the right second proximal phalanx revealed the possible presence of metal fragments below the surface of the bone. To verify the presence of lead in a nondestructive manner, the bone was scanned with a 1.5-MeV proton beam. PIXE analysis showed that lead was present only in the vicinity of the fragments previously detected in the radiographs. A study of gunshot residue in bone shows that the distribution of lead around the bullet hole is independent of the firing distance for distances greater than 0.6 m.     

Measuring the thickness of facial soft tissues using nuclear magnetic resonance tomography for the purpose of identification

Nuclear spin tomography since its beginnings in the seventies has steadily gained in importance as a method of examination in medical diagnostics as it produces a picture. In the field of forensic medicine the NMR technique as used for anatomic-anthropologic issues attempting to identify skulls this is a valuable supplement to an extension of the existing methods of investigation. The results of a measurement of the thickness of soft facial tissue in a live test person is shown as compared to measures obtained by sonography.     

Suicide in Fulton County, Georgia (1975-1984)

Demographic and trend analysis of 881 consecutive suicides in blacks and whites is presented. For the years 1975 through 1984, the suicide rate was 15.1/100 000 and did not significantly change. White males were overrepresented in all age groups, had an overall suicide rate of 34.9, and showed a small but statistically significant increase in rate which was not accounted for by any specific age group. White females, in general, were represented in proportion to their prevalence in the population, and those ages 20 to 24 demonstrated an increasing suicide rate which was small. Black males were at highest risk in their twenties, showed no significant trends, and were also represented near their prevalence in the population. Black females of all ages were underrepresented, and had low suicide rates which decreased with time. No significant rate changes were noted for teenagers or the elderly. Firearms was the method of choice in all groups, although methods varied with age, race, and sex, and male children preferred hanging. Small but significant increases were noted for the prevalence of nondrug methods in females and carbon monoxide deaths in white males. Similarities and differences to larger scale studies are discussed. Suicide may have characteristics unique to given geographical areas and pervasive to all areas. The authors advocate study and publication of local data to clarify further the nature of suicide.     

Detection of cocaine metabolite in perspiration stain, menstrual bloodstain, and hair

Low nanogram and picogram quantities of cocaine metabolite equivalents were detected in extracts from perspiration stains, menstrual bloodstains, and hair using radioimmunoassay. The theory of drug inclusion in hair and its significance are discussed.     

Blood droplet dynamics--I

The interpretation of bloodstain patterns at crime scenes has received increased attention in recent years. Important to an understanding of this is knowledge of the fundamentals of blood droplet formation and impact dynamics. A review of the literature reveals that a considerable amount of work has been done with aqueous drop dynamics. Workers in the forensic science area seem to have been unaware of this. In addition, some of the most important and comprehensive early work with blood droplet dynamics seems to have been forgotten. It is not cited in more recent publications dealing with bloodstain pattern interpretation. This literature is reviewed and discussed as well. The present study presents results of experiments with blood droplet dynamics and high-speed photographs of blood droplet impacts on stationary target surfaces. Some longstanding misconceptions of importance to forensic scientists engaged in crime scene reconstruction are discussed.     

Histochemical demonstration of phenobarbital by immunocytochemistry

A method for the demonstration of the topographical distribution of phenobarbital at the cellular level in various tissues was established. Mice that had been exposed to various doses of phenobarbital by intraperitoneal injection were killed, and their tissues were fixed with 0.1 M phosphate buffer solution (pH 7.4) containing paraformaldehyde and glutaraldehyde. Thereafter, paraffin and frozen sections were made and stained by the indirect immunoperoxidase method using antisera obtained from commercial sources and used for the immunochemical assay of the blood level of phenobarbital in clinical medicine. A specific positive reaction was observed solely in testing the intoxicated tissues, and this reaction was inhibited when phenobarbital was added to the antisera. The minimal sensitivity of the positive reaction, which can be discerned by observing the stained slides macroscopically, was in the range of 10 mg/kg. Thus, the diagnosis of phenobarbital intoxication in the forensic autopsy can be made by immunohistochemistry. A positive reaction was found in various tissue cells, including nerve cells, myelin sheaths, glia cells, hepatocytes, cells of the alveolar and bronchial wall, epithelial cells of the distal part of the renal tubules, and so forth. Endothelial cells of the capillaries in all tissues gave a strong positive reaction. The immunocytochemical electron microscopy of the hepatocytes revealed that the positive reaction in the cytoplasm was located solely in the intraluminal space of the smooth endoplasmic reticulum. These results indicate some interesting aspects of the pharmacokinetics of phenobarbital in vivo. It is expected that the antisera, which are used widely for the assay of the blood concentration of various drugs (phenobarbital, amphetamines, morphine, and so forth), may be regarded as excellent reagents for immunocytochemistry. This clearly indicates that morphological evidence in toxicology, which had so far remained obscure, can be easily obtained by applying these antisera against various drugs.