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.     

The Effects of Juror Anonymity on Jury Verdicts

This study examined the effects of anonymity on jurors' verdicts and on jurors' feelings of accountability for their jury's verdicts. Twenty four-person anonymous juries and 20 four-person nonanonymous juries rendered individual and group verdicts for three student defendants charged with selling drugs on a school campus. When unanimous guilty verdicts were reached, juries imposed one of five punishments. Finally, jurors completed postdeliberation opinion and accountability questionnaires. As predicted, anonymous juries showed a higher rate of conviction (70%) than did nonanonymous juries (40%) when the evidence against the defendant was strong, supporting the hypothesis that anonymity would have a greater effect for situations in which there was relatively strong evidence of the defendant's guilt. Anonymous juries imposed the harshest punishment (expulsion) significantly more often than did nonanonymous juries. Contrary to predictions from differential self-awareness theory, anonymous juries did not report feeling less accountable than did nonanonymous juries. However, anonymous juries did see the process as significantly more fair than did identifiable juries.     

3-Methoxytyramine in the putamen as a gauge of the postmortem interval

The armamentarium of the forensic thanatologist includes the examiner's subjective assessment of bodily changes together with comprehensive evaluation of environmental and associated factors to estimate the postmortem interval (PMI). Of the various objective means, postmortem accumulation of potassium in vitreous humor is a widely used gauge. In view of the considerable variability inherent in these techniques, an additional marker with greater accuracy would be a welcome supplement to these indices. We have developed a method of estimating PMI from the level of 3-methoxytyramine (3-MT) in the dorsal putamen of the brain. The supernatant of a sample of putamen, sonicated in 6 volumes (weight/volume) of 0.1 M perchloric acid and centrifuged at 51 000 times gravity for 10 min, was analyzed for 3-MT using high-pressure liquid chromatography with electrochemical detection. The change of 3-MT in the putamen is linearly related to the PMI (range: 5.5 to 60 h), irrespective of patient age (1 to 84 years). This observation is attributable to several factors, including high substrate (dopamine) concentration, preservation of catechol-O-methyl transferase activity, and an inactivation of monoamine oxidase activity, as a result of a decrease in tissue pO2.