Average Probability that a "Cold Hit" in a DNA Database Search Results in an Erroneous Attribution

Abstract:  We consider a hypothetical series of cases in which the DNA profile of a crime-scene sample is found to match a known profile in a DNA database (i.e., a "cold hit"), resulting in the identification of a suspect based only on genetic evidence. We show that the average probability that there is another person in the population whose profile matches the crime-scene sample but who is not in the database is approximately 2( N  −  d ) p _A , where N is the number of individuals in the population, d is the number of profiles in the database, and p _A is the average match probability (AMP) for the population. The AMP is estimated by computing the average of the probabilities that two individuals in the population have the same profile. We show further that if a priori each individual in the population is equally likely to have left the crime-scene sample, then the average probability that the database search attributes the crime-scene sample to a wrong person is ( N  −  d ) p _A .     

Detection and Identification of Explosive Particles in Fingerprints Using Attenuated Total Reflection-Fourier Transform Infrared Spectromicroscopy

Abstract:  The application of attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectromicroscopy for detection of explosive particles in fingerprints is described. The combined functions of ATR-FTIR spectromicroscopy are visual searching of particles in fingerprints and measuring the FTIR spectra of the particles. These functions make it possible to directly identify whether a suspect has handled explosives from the fingerprints alone. Particles in explosive contaminated fingerprints are either ingredients of the explosives, finger residues, or other foreign materials. These cannot normally be discriminated by their morphology alone. ATR-FTIR spectra can provide both particle morphology and composition. Fingerprints analyzed by ATR-FTIR can be used for further analysis and identification because of its non-destructive character. Fingerprints contaminated with three different types of explosives, or potential explosives, have been analyzed herein. An infrared spectral library was searched in order to identify the explosive residues. The acquired spectra are compared to those of finger residue alone, in order to differentiate such residue from explosive residue.     

Histological Determination of the Human Origin of Bone Fragments

Abstract:  A frequently encountered task in the forensic scenario is verification of the human origin of severely degraded fragments of bone. In these cases histological methods which consider osteon size and morphology can prove to be useful. The authors in the present study verify the applicability of published algorithms to flat and subadult bones from human, dog, cat, cow, rabbit, sheep, pig, chicken, quail, and turkey samples. Metric analysis was performed on 2031 Haversian canals. Analyses carried out on human samples confirmed a success rate of around 70% on long adult bones; however the percentage of wrong answers was particularly high in the case of newborns and older subadults as well as on flat bones in general. Results therefore suggest that such regression equations should be limited only to bone fragments from long adult bones.     

The Effects of Soil Environment on Postmortem Interval: A Macroscopic Analysis

Abstract:  Burial environment, in particular soil moisture, has a significant impact on the type, rate, and extent of bone degradation, which ultimately affects estimations of the postmortem interval (PMI). The purpose of this research is to determine the effects of soil moisture on the color, weight, condition, and texture of bone as it relates to the PMI. Bone changes occurring over two different time intervals (2 and 5 months) were examined using 120 sus scrofa leg bones. During each time interval bones were buried in two soil environments, one of which was drier than the other. The bones in both environments lost weight over time but the net weight loss was greater for bones in the higher moisture environment. There was no change in color, texture, or overall condition, indicating that 150 days is not long enough for such alterations to occur, regardless of the moisture level of the burial environment.     

Potentially Lethal Behaviors Associated With Rapid Eye Movement Sleep Behavior Disorder: Review of the Literature and Forensic Implications

Abstract:  Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by loss of the muscle atonia of REM sleep, with release of complex and violent behaviors that are often attempted dream-enactments. This study reviewed the literature on RBD with regard to potentially lethal behavior. A total of 39–41 clinical cases of RBD associated with potentially lethal behaviors to self and/or others were found, involving a child and adults of all age groups, that manifested as choking/headlock ( n  = 22–24), defenestration/near-defenestration ( n  = 7), and diving from bed ( n  = 10). A total of 80.8% ( n  = 21) were males; 19.2% ( n  = 5) were females; mean age was 65.6 ± (SD) 13.8 years (range: 27–81 years, and a child). (Gender/age data were not listed in the remaining cases.) An etiologic association of RBD with a neurologic disorder (or with pharmacotherapy of psychiatric disorders, n  = 4) was present in 21–23 patients. Thus, RBD carries well-documented, potential forensic consequences during RBD episodes that could possibly have been misinterpreted as suicidal or homicidal behavior.     

Skull Fracture with Brain Expulsion in a One-Level Jumping-Fall

Abstract:  Here presented is the case of a one-level jumping-fall with extensive skull fractures and brain expulsion. The body was found on the basement floor at the foot of the stairs. At the autopsy, the skull was extensively fractured, with about half of the brain expulsed several feet away from the body. The cause of death was established as a craniocerebral trauma with brain expulsion. The circumstances and manner of death were still unclear at that time. A low fall seemed very unlikely considering the severity of the skull and brain damage. The police investigation clearly revealed that the man, in a paranoid psychotic state, attacked his wife with a knife and then was witnessed by his children to have hit his head several times with a hammer. Afterwards, they saw him running to the top of the basement stairs and jumping to the bottom of the stairs head first.     

The Relationship Between Deprivation and Forensic Opportunities with Stolen Vehicles

Abstract:  Collection and interpretation of forensic intelligence (primarily through DNA and fingerprint identifications) is an integral part of the investigation of criminal offenses ranging from burglary and vehicle crime to major crime. The forensic contribution depends not only on the successful recovery of material, but also the ability to identify potential offenders and apply this intelligence to solve the crime. This study examines burglary and vehicle crimes investigated by Northamptonshire Police (U.K.) by analyzing relationships between deprivation of a crime location and the recovery and identification of DNA and fingerprint material. The results show that, for stolen vehicles, although significantly more forensic material (both DNA and fingerprints) is recovered and identified in more deprived neighborhoods, this does not lead to a corresponding increase in solved cases. These findings are considered in relation to previous studies, which have advocated the prioritization of resources at crime scenes most likely to yield forensic material.     

Foreigners Dying in Istanbul

Abstract:  The study included 411 deaths selected from 14,647 medicolegal deaths autopsied in the Morgue Department of Forensic Medicine Institute Directorate, affiliated with the Ministry of Justice, between 1998 and 2002. Data were collected from court documents, coroner's investigation reports, and autopsy reports. The parameters of age, gender, nationality and origin, cause and place of death in foreigners dying in Istanbul were evaluated in the study. Out of 14,647 medicolegal deaths, 3.5% were foreigners from 34 different nationalities. The nationality with the highest rate of foreigner deaths (34%) was Romanian. Out of 411 deaths, 74.3% were male and 25.7% were female. Of all cases, 64.4% were tourists visiting Istanbul and 35.6% had a job in Istanbul. Of 146 foreigners employed in Istanbul, 94.5% did not have a work permit, while only 5.5% had a work permit.     

Morphine Concentrations in Stomach Contents of Intravenous Opioid Overdose Deaths

Abstract:  Death caused by heroin overdose is almost always the result of intravenous injection of the drug in Australia. We briefly describe a case where a heroin overdose was initially thought to be the result of oral ingestion of the drug, primarily as a result of higher concentrations of morphine in stomach contents than in blood. During the subsequent criminal trial and investigation, however, the issue of the entero-hepatic circulation of morphine was raised as a possible reason for the presence of morphine in the stomach contents. In this study, we report on the distribution of opioids in blood, stomach contents, urine, liver, and bile in 29 deaths caused by intravenous heroin overdose. The mean total and free blood morphine concentrations were 0.60 and 0.32 mg/L , respectively, and the mean stomach contents total morphine concentration was 1.16 mg/kg. All cases had detectable morphine in the stomach contents, and 24 of 29 cases (83%) had higher concentrations of total morphine in stomach contents than in blood. The mean total morphine concentration in bile was c. 100 times that in blood, and the liver total morphine concentration averaged twice that of blood levels. We conclude that the entero-hepatic circulation of morphine and subsequent reflux of duodenal contents back into the stomach can result in the deposition of morphine in gastric contents. Consequently, the relative levels of opioids in blood and stomach contents cannot be used to determine the site of administration of the drug.     

Unexpected Death in Elephantiasis Due to an Abnormal Life-Style

Abstract:  A 22-year-old man was found dead after he had continued to sit on a reclining chair for 2 years. He had consumed an unbalanced diet, kept wearing the same pair of socks and never washed himself for the term. His skin of bilateral crura developed into elephantiasis with severely festered ulcers on its surface. At autopsy, subcutaneous edema was significant in his lower limbs, and chronic circulatory disturbance of lymphoducts and veins was observed histologically. There were no crucial findings to account for chronic edema in the lower limbs. It has been reported that maintaining a seated posture obstructs both lymphoducts and veins because of bending the groin, decreases their return flow by inducing muscular atrophy, and causes subcutaneous edema in the lower limbs. Oligotrophia and dirt on his limbs might have exacerbated the chronic edema in elephantiasis. We concluded that a long-term abnormal life-style had caused fatal elephantiasis.