Showing papers in "Journal of Forensic Sciences in 1996"

Initial studies on insect succession on carrion in Southwestern British Columbia

Abstract: This is the first report of an ongoing study of insect succession on carrion in British Columbia. Pig (Sus scrofa L.) carcasses were used as human models to determine insect succession on carrion over time in an open, sunlit, rural area in summer in southwestern British Columbia, in order to begin a database of insect colonization of carrion in this province. Insects colonized the remains in sequence over 271 days postmortem. Some species, in particular, those in the Piophilidae and Dermestidae families, were collected earlier in the decomposition process than usually reported from other regions, probably indicating geographic variation in colonization times. Maggot activity raised internal carcass temperature, but minimum and maximum internal temperatures fluctuated more than ambient temperatures, with diel internal temperature differences of more than 35°C. Soil fauna also showed considerable changes in identity and number of species, and had not returned to pre-carcass levels 271 days postmortem.

Economic dimensions of slip and fall injuries

Abstract: This paper provides an update of annual economic costs imposed by fall injuries. Such costs include medical, rehabilitation, hospital costs, and the costs of morbidity and mortality. These costs are projected to the year 2020, based on changing demographic trends. The market for slip and fall injury prevention is analyzed for the elderly and for those in the workplace-two high risk groups. Questions as to whether this market operates in a socially desirable manner, or whether government intervention is justified on efficiency grounds, are considered. Essential aspects of cost-benefit analysis are reviewed in the context of a prospective evaluation of interventions to prevent slip and fall injuries. THe cost-benefit analysis framework is applied to part of the FICSIT experiment (a major intervention to reduce falls among the elderly) and to recent revisions in Occupational Safety and Health Administration regulations directed at reducing workplace falls.

The Sexually Sadistic Serial Killer

Abstract: This article explores characteristics and crime scene behavior of 20 sexually sadistic serial murderers. The pairing of character pathology with paraphilic arousal to the control and degradation of others is examined as it manifests itself in their murders. Commonalities across murders and across murderers are highlighted, i.e., the execution of murders that are well-planned, the use of preselected locations, captivity, a variety of painful sexual acts, sexual bondage, intentional torture, and death by means of strangulation and stabbing.

A Bayesian approach to adult human age estimation from dental observations by Johanson's age changes.

Abstract: Much of the data which appears in the forensic and archaeological literature is ordinal or categorical. This is particularly true of the age related indicators presented by Gustafson in his method of human adult age estimation using the structural changes in human teeth. This technique is still being modified and elaborated. However, the statistical methods of regression analysis employed by Gustafson and others are not particularly appropriate to this type of data, but are still employed because alternatives have not yet been explored. This paper presents a novel approach based upon the application of Bayes' theorem to ordinal and categorical data, which overcomes many of the problems associated with regression analysis.

Predicting aggressive and socially disruptive behavior in a maximum security forensic psychiatric hospital

Abstract: The predictive utility of Hare, Hart, and Cox's Psychopathy Checklist Screening Version (PCL:SV) was assessed utilizing a sample of forensic psychiatric patients from Vernon State Hospital in Vernon, Texas. A sample of 55 patients were interviewed and rated on the PCL:SV. During a six month follow up, occurrences of self-harm (suicide attempts and self mutilation), aggression (verbal abuse and threats, irritability, belligerence, and fighting) escape potential (threats and attempts), and treatment refusal (medication, tests, and physician's appointments) were rated. Separate stepwise multiple regression analyses were performed utilizing patient's age, type of charges, documented history of alcohol/drug abuse and the PCL:SV as predictor variables. Results indicate that the PCL:SV is predictive of aggression and treatment noncompliance.

Methamphetamine and Driving Impairment

Abstract: Following a review of the effects of methamphetamine on human performance, actual driving and behavior were evaluated in 28 cases in which drivers arrested or killed in traffic accidents had tested positive for methamphetamine. The circumstances surrounding the arrest or accident were examined, together with any observations by the arresting officer regarding behavioral irregularities. The investigators also made a determination of culpability. Most of the arrests resulted from accidents in which the driver was determined to be culpable. Typical driving behaviors included drifting out of the lane of travel, erratic driving, weaving, speeding, drifting off the road, and high speed collisions. Behavioral manifestations of methamphetamine use in arrestees included rapid or confused speech, rapid pulse, agitation, paranoia, dilated pupils, violet or aggressive attitude. Combined alcohol and methamphetamine use was uncommon, however use of marijuana was evident in about one third of the cases. In addition to impairing judgment and increasing risk taking, the effects of withdrawal from methamphetamine use including fatigue, hypersomnnolence, and depression are likely contributors to many of these accidents. A consideration of the literature and the cases discussed here, leads to the conclusion that methamphetamine at any concentration is likely to produce symptoms that are inconsistent with safe driving.

Identification of war victims from mass graves in croatia, bosnia, and herzegovina by the use of standard forensic methods and dna typing

Abstract: The postmortem remains of sixty-one war victims were excavated from 6 mass graves in Bosnia and Herzegovina one and a half years after interment. Using standard identification methods, including the matching of medical and dental records, the recognition of distinguishing characteristics such as the use of clothing and belongings, and video superimposition, 35 persons were identified. For the remaining 26 persons identification efforts continue. DNA typing was performed at the HLA DQA1 locus and five PM system loci. Results from DNA typing were confirmed by other methods. DNA profiles of family members of 150 missing persons are now being developed using the 6 loci. These DNA profiles will then be compared with those generated from the bone and teeth remains of the unidentified victims.

Shaken babies--some have no impact injuries.

Abstract: One study has questioned the validity of shaking as a mechanism of head injury in children. A prospective, postmortem study investigated 80 deaths from head trauma to identify the roles of shaking and direct impacts. Evidence of shaking was defined as two or more of the following criteria: 1) finger marks and/or rib fractures, 2) subdural and/or subarachnoid hemorrhage, or 3) a history of vigorous shaking. Shaking to the exclusion of other head trauma was defined as the presence of two or more of the above criteria together with the complete absence of scalp or skull injuries. Nine (11.3%) of the 80 study deaths qualified as exclusively shaking injuries by this definition. Thirty (37.5%) of the deaths had direct injuries as well as two of the criteria of shaking; these deaths were classified as combined shaking and blunt trauma. Forty-one (51.3%) of the deaths had impact injuries without having two of the criteria of shaking. We reviewed the extent of ocular injuries in all the cases. We found ocular hemorrhages with increased frequency in cases with two or more of the criteria of shaking compared to cases with only impact mechanism of injury. Retinal hemorrhages continue to show themselves to be a good marker of infants injured by vigorous, intentional shaking. This study likewise confirms the observations of others that most, but not all, shaken babies have impact injuries as well.

Attribution of foot bones to sex and population groups

Abstract: Although cranial and pelvic bones are the preferred skeletal material used by forensic anthropologists to assign unknown individuals to their most probable sex and population (racial) groups, these remains may be unavailable. This paper presents models for classification using metatarsals, proximal pedal phalanges, and the first distal phalanx of the foot. Measurements include lengths and mediolateral and dorsoplantar widths of these foot bones. Four samples of 40 individuals each (black and white males and females) comprise the dataset. Models were developed separately for right and left sides. Three models are provided for each side: a metatarsal model, a proximal phalangeal model, and a combination model involving selected metatarsal and phalangeal measurements. A stepwise discriminant procedure was used for variable selection, with some highly correlated (r > 0.85) variables subsequently removed. The metatarsal models correctly assign approximately 77-84% of individuals to their correct sex and population groups; proximal phalangeal models yield correct assignments in 70-72% of cases, and the combination models give correct classifications in 87% of cases. Models exchanging variables selected from one side for corresponding variables on the other show discriminating power ranging from approximately 67-86%. More conservative "jackknife" estimates give correct assignments in 64-82% of cases. When these models are used for classification of sex alone, 86.2-93.7% ("jackknife" range, 84.3-91.2%) of cases are correctly classified; for race alone, 78.6-96.2% ("jackknife" range, 75.5-92.4%).

Variability of the blood/breath alcohol ratio in drinking drivers

Abstract: The ratio of blood-alcohol concentration (BAC) to breath-alcohol concentration (BrAC) was determined for 799 individuals apprehended for driving under the influence of alcohol (DUI) in Sweden. The BrAC was determined with an infrared analyzer (Intoxilyzer 5000S) and venous BAC was measured by headspace gas chromatography. The blood samples were always taken after the breath tests were made and the average time delay was 30 +/- 12 min (+/- SD), spanning from 6 to 60 min. The blood/breath ratios of alcohol decreased as the time between sampling blood and breath increased (F = 15.4, p 0.05). The overall mean time-adjusted blood/breath ratio (+/- SD) was 2407 +/- 213 and the 95% limits of agreement (LOA) were 1981 and 2833. During 1992, 1993, and 1994, the mean blood/breath ratios of alcohol were remarkably constant, being 2409 +/- 288, 2407 +/- 206, and 2421 +/- 235, respectively, and the values were not significantly influenced by the person's age, gender, or blood-alcohol content. In 34 individuals (4.3%), the blood/breath ratio was less than 2100 after compensating for metabolism of alcohol between the times of sampling blood and breath. This compares with 156 individuals (19.6%) having a blood/breath ratio less than 2100:1 without making any correction for the metabolism of alcohol.

Mechanisms of unexpected death in infants and young children following foreign body ingestion.

Abstract: Fatal foreign body ingestion in childhood usually results in sudden and unexpected death from acute upper airway occlusion. The most common age range for such episodes is one to three years. However, a variety of different mechanisms of death due to ingested foreign bodies may occur in children, including hemorrhage, acute cardiac tamponade, arrhythmia, centrally mediated respiratory arrest and sepsis. Sudden death may follow a protracted asymptomatic period and may also be due to foreign bodies impacted in the esophagus. A review of cases has been undertaken (N = 10; age = three and one-half months to seven years; M:F = 9:1), which demonstrates the variety of lethal processes that may occur, the range of materials involved and the different anatomical sites where problems can result.

Sex determination by discriminant function analysis of lateral radiographic cephalometry

Abstract: The present work is an attempt to develop a new method to determine sex from the skull with lateral radiographic cephalometry and discriminant function analysis. The superciliary ridges, frontal sinuses, external occipital protuberance, and mastoid processes were adopted as objects of lateral radiographic cephalometric measurements. With discriminant functions created from 18 established cephalometric variables, a total of 100 cases were classified into two sexual groups with 100% accuracy in a random sample of Taiwanese adults. Therefore, we may obtain a much greater reliability of sex determination from skulls according to this newly developed technique.

Postmortem Distribution and Redistribution of Morphine in Man

Abstract: This study evaluated both site dependent differences and time dependent changes in postmortem morphine concentrations in man. In 32 deaths involving morphine, left ventricular blood, femoral blood, and cisternal cerebrospinal fluid, were collected as soon after death as possible (T1), and collected again together with iliac blood at the time of autopsy (T2). Samples were analyzed for morphine by radioimmunoassay. No evidence was found for changes in morphine concentration with respect to time at either central or peripheral sites, or in the cerebrospinal fluid. Ventricular blood morphine concentrations were however consistently higher than those in the peripheral compartment, represented by either femoral or iliac blood. This was particularly true when the ventricular morphine concentration exceeded 0.300 mg/L. At peripheral sites, femoral and iliac blood morphine concentrations were well correlated with each other, making either an appropriate site for collection of peripheral blood for toxicological testing.

Fracture of the Hyoid Bone in Strangulation: Comparison of Fractured and Unfractured Hyoids from Victims of Strangulation

Abstract: The hyoid is the U-shaped bone of the neck that is fractured in one-third of all homicides by strangulation On this basis, postmortem detection of hyoid fracture is relevant to the diagnosis of strangulation However, since many cases lack a hyoid fracture, the absence of this finding does not exclude strangulation as a cause of death The reasons why some hyoids fracture and others do not may relate to the nature and magnitude of force applied to the neck, age of the victim, nature of the instrument (ligature or hands) used to strangle, and intrinsic anatomic features of the hyoid bone We compared the case profiles and xeroradiographic appearance of the hyoids of 20 victims of homicidal strangulation with and without hyoid fracture (n = 10, each) The fractured hyoids occurred in older victims of strangulation (39 +/- 14 years) when compared to the victims with unfractured hyoids (30 +/- 10 years) The age-dependency of hyoid fracture correlated with the degree of ossification or fusion of the hyoid synchondroses The hyoid was fused in older victims of strangulation (41 +/- 12 years) whereas the unfused hyoids were found in the younger victims (28 +/- 10 years) In addition, the hyoid bone was ossified or fused in 70% of all fractured hyoids, but, only 30% of the unfractured hyoids were fused The shape of the hyoid bone was also found to differentiate fractured and unfractured hyoids Fractured hyoids were longer in the anterior-posterior plane and were more steeply sloping when compared with unfractured hyoids These data indicate that hyoids of strangulation victims, with and without fracture, are distinguished by various indices of shape and rigidity On this basis, it may be possible to explain why some victims of strangulation do not have fractured hyoid bones

Standardization Model for Describing the Extent of Burn Injury to Human Remains

Abstract: This paper provides a model for standardizing descriptions of the extent of burn injury to human bodies consumed in fire. Its intent is to simplify and make comparable case reports and legal descriptions by medical examiners, pathologists, crime scene investigators, forensic odontologists, forensic anthropologists, fire fighters, paramedics, and others responsible for recovery, analysis, or identification of burn victims. The Crow-Glassman scale (CGS) is divided into five levels depicting increasing destruction to the body relative to burn injury. Each level relates to a unique set of circumstances that may affect on the recovery procedure, analysis strategy for identification, and choice of personnel most suited for making identifications.

Evaluating DNA Profile Evidence When the Suspect Is Identified Through a Database Search

Abstract: The paper is concerned with the strength of DNA evidence when a suspect is identified via a search through a database of the DNA profiles of known individuals. Consideration of the appropriate likelihood ratio shows that in this setting the DNA evidence is (slightly) stronger than when a suspect is identified by other means, subsequently profiled, and found to match. The recommendation of the 1992 report of the US National Research Council that DNA evidence that is used to identify the suspect should not be presented at trial thus seems unnecessarily conservative. The widely held view that DNA evidence is weaker when it results from a database search seems to be based on a rationale that leads to absurd conclusions in some examples. Moreover, this view is inconsistent with the principle, which enjoys substantial support, that evidential weight should be measured by likelihood ratios. The strength of DNA evidence is shown also to be slightly increased for other forms of search procedure. While the DNA evidence is stronger after a database search, the overall case against the suspect may not be, and the problems of incorporating the DNA with the non-DNA evidence can be particularly important in such cases.

Paternity exclusion by DNA markers: effects of paternal mutations.

Abstract: In parentage testing when one parent is excluded, the distribution of the number of loci showing exclusion due to mutations of the transmitting alleles is derived, and it is contrasted with the expected distribution when the exclusion is caused by nonpaternity. This theory is applied to allele frequency data on short tandem repeat loci scored by PCR analysis, and VNTR data scored by Southern blot RFLP analysis that are commonly used in paternity analysis. For such hypervariable loci, wrongly accused males should generally be excluded based two or more loci, while a true father is unlikely to be excluded based on multiple loci due to mutations of paternal alleles. Thus, when these DNA markers are used for parentage analysis, the decision to infer non-paternity based on exclusions at two or more loci has a statistical support. Our approach places a reduced weight on the combined exclusion probability. Even with this reduced power of exclusion, the probability of exclusion based on combined tests on STR and VNTR loci is sufficiently large to resolve most paternity dispute cases in general populations.

Site to site variability of postmortem drug concentrations in liver and lung

Abstract: We evaluated postmortem diffusion of gastric drug residue into tissues and blood in eight suicidal overdoses. Analyses were performed on liver (five sites), lung (four sites), spleen, psoas muscle and kidney (left and right), blood (peripheral and torso), vitreous, pericardial fluid, bile and, urine as well as residual gastric contents. Standard analytical techniques and instrumentation gas chromatograph/mass spectrometer and high performance liquid chromatography (GC-MS and HPLC) were used throughout. These case studies confirm previous studies of an animal and human cadaver model of gastric diffusion, in that in several instances there was drug accumulation in the left posterior margin of the liver and, to a lesser extent, the left basal lobe of the lung. Uncontrollable variables, such as postmortem interval, refrigeration before autopsy, and position of the body appear to influence significantly drug accumulation in a specific site. We suggest that autopsy sampling techniques should be standardized on blood taken from a ligated peripheral (preferably femoral or external iliac) vein, and liver from deep within the right lobe.

The Criminal Investigation Process and the Role of Forensic Evidence: A Review of Empirical Findings

Abstract: Highlights from the major empirical studies on the criminal investigation process, and the role played by physical evidence in that process, are reviewed in light of findings from empirical studies on the effects of forensic analyses on criminal cases. The review reveals that most criminal cases do not involve the use of any physical evidence and that such evidence, even when available, is seldom seen by police detectives as having any intrinsic value. Detectives use physical evidence primarily to strengthen their position vis a vis the suspect's for the purpose of clearing cases by confession. Nevertheless, some research shows that physical evidence improves clearances and convictions in burglary and robbery cases, which traditionally have low case resolution rates. Enhancement of the use and value of physical evidence to investigators, crime laboratory specialists, and others involved in criminal processing requires improved communication and collaborative efforts. Training of police and prosecutors should be particularly emphasized because they have the most to say about whether and how physical evidence is used in the investigation of criminal cases.

Continuous river monitoring of the diatoms in the diagnosis of drowning.

Abstract: The diagnosis of drowning is one of the most difficult in forensic pathology Diatom analysis has been proposed to provide supportive evidence of drowning but the reliability and applicability of quantitative and qualitative diatom analysis in the diagnosis of drowning is still disputed in the literature In order to further examine such cases, the authors report the development of a water monitoring system based on algae performed each month at three aquatic locations where drowning victims are frequently found Water samples and stones were taken from the surface and from the bed of the river This protocol was performed during 1993 with analyses both on water samples and human tissue samples (30 bodies) The diatom profile of the drowning sites was compared with the tissue analysis The extraction of diatoms from the tissues was performed with an enzymatic digestion method using Proteinase K Results indicate that the monitoring of river diatom populations is an accurate method of generating profiles of the river flora, which can then be compared with the diatom genera found in tissues

On Pathways for Small Molecules Into and Out of Human Hair Fibers

Abstract: This paper represents an experimental approach of histology of the human hair fiber in dyeing and diffusion phenomena and its contribution to the interpretation of hair analysis results for drug abuse. Rhodamine B was applied to human hair fibers from either aqueous solution or methanol/ethanol solvent. The experiments were performed on natural hair of different ethnic groups as well as on extensively bleached hair strands. The microscopical study of the pathway of diffusion of rhodamine B into the hair fibers indicated that the reagent had entered the unmodified fibers at the scale edges between the cuticle cells. At the beginning of the diffusion process intercellular diffusion was the preferred route predominantly along the nonkeratinous regions of the cell membrane complex (CMC) and intermacrofibrillar cement. Penetration into the high sulfur regions of the fiber occurred as dyeing in aqueous solution proceeded and resulted in evenly stained cross sections. The dye distribution pattern observed in natural hair exposed to nonaqueous solution showed that rhodamine B did not penetrate the cortex cells as easy as from aqueous solution and selectively stained nonkeratinous regions only. The determination of the amount of dye taken up by the fibers by spectrophotometric analysis demonstrated that samples diffusion generally increased by time and temperature. It also depended on the morphology of the hair sample. The penetration of rhodamine B from aqueous solution was much greater than from methanol/ethanol solvent.

Postmortem stability of cocaine and cocaethylene in blood and tissues of humans and rabbits.

Abstract: A study was conducted to examine the postmortem stability of cocaine and cocaethylene in rabbit blood and tissues, and to determine whether cocaethylene is produced in decomposed human specimens containing cocaine and endogenous ethanol. Heart blood, liver, brain and femoral muscle taken from rabbits 20 min after oral administration of 20 mg/kg cocaine together with 2 g/kg ethanol were kept at 20-25 degrees C for 5 days. Cocaine and cocaethylene concentrations were in the order brain > liver > muscle > blood, and showed very large intersubject variations at the time of death. Cocaine was degraded rapidly in the blood and liver. However, 12.0 +/- 8.5% and 26.2% +/- 19.4% of the original cocaine was still detectable in the brain and muscle, respectively. Cocaethylene was degraded more slowly than cocaine in all of the specimens. The pH of the blood remained around 7.4 during a 5-day period; all the other specimens showed pH values of 6.2-6.7 on and after the first day postmortem. When 10,000 ng/g cocaine was incubated with decomposed human blood, liver, brain and muscle homogenates containing 0.29-0.60 mg/g endogenous ethanol at 20-25 degrees C and 37 degrees C, no change in cocaine concentration was observed during the study period of 24 h, and no cocaethylene was detected. The pH values of the homogenates were within the range 4.2 to 5.2 at the beginning of the experiment. It was found that: 1) cocaethylene was more stable in postmortem specimens than cocaine; 2) muscle as well as brain was specimen of choice for detecting cocaine and cocaethylene postmortem; 3) cocaine was resistant to decomposition under acidic conditions; and 4) putrefactive bacteria had no ability to produce cocaethylene even in the presence of cocaine and endogenous ethanol.

Deaths due to foreign body aspiration in children: the continuing hazard of toy balloons.

Abstract: Asphyxia due to aspiration of a foreign body is a common cause of accidental death in children. Foreign body aspiration is the most likely cause of accidental fatalities in children under 1-year-of-age. Children may die due to airway obstruction by food objects such as hot dogs, nuts, candies, grapes, seeds, and egg shells. Non-food objects such as balloons, coins, pop tops of beverage cans, pills, safety pins, ball bearings, marbles, and baby powder also may be fatally aspirated. To better understand and help prevent this well recognized health risk to children, we reviewed 10 years of cases at the Cook County Medical Examiner's Office in which deaths in children 14-years-of-age and younger were due to aspiration of foreign objects. The most common item that caused fatal aspiration in our series was a toy balloon.

The Use of Activated Charcoal Strips for Fire Debris Extractions by Passive Diffusion. Part 1: The Effects of Time, Temperature, Strip Size, and Sample Concentration

Abstract: The introduction of commercially produced activated charcoal strips into fire, debris analysis has provided an easy, efficient and cost effective method for accelerant extraction. Several parameters associated with passive diffusion extraction of fire debris using activated charcoal require consideration in order to obtain a truly representative sample of the accelerant. This study investigated the effects of time, temperature, charcoal strip size and sample concentration on the adsorption of common accelerants. Notable displacement of specific volatile components, similar to the break-through noted in dynamic systems, occurred under certain extreme conditions. An analysis protocol was developed to minimize these effects.

A Novel Method for the Analysis of Gasoline from Fire Debris Using Headspace Solid-Phase Microextraction

Abstract: Solid-phase microextraction (SPME) has been adapted for the analysis of gasoline in fire debris. Compared to traditional passive headspace concentration (activated charcoal strip), the SPME method presented here was found to be faster, simpler and have a higher sensitivity. This method also eliminates the need for the highly flammable and toxic solvent carbon disulfide.

Assessing the Unique Characteristics of Close-Proximity Soil Samples: Just How Useful Is Soil Evidence?

Abstract: An evaluation of current techniques used in the forensic analysis of soils and geologic evidence. Research was performed to determine the discriminative qualities of the various procedures to discern at what point soils become indistinguishable from one another. Included in this research is an assessment of the techniques from an analyst standpoint to determine what level of advanced mineralogical examination is required to segregate one sample from another. One hundred samples were collected from three different sites; a beach, an island isolated by a river, and a bus parking lot. The samples were analyzed utilizing color determination, particle size distribution analysis and mineralogical profiles of the twenty-five most common soil minerals. Of the three hundred samples examined, over one-half could be discriminated by color alone, the remainder needing only particle size distributions analysis for differentiation, negating the need for lengthy mineralogical examinations. These examinations were conducted with very inexpensive equipment and calculations which could be used with a minimum of training and cost.

Morphological classification of facial features in adult Caucasian males based on an assessment of photographs of 50 subjects.

Abstract: Fifty sets of photographs showing facial features of Caucasian males aged 18 to 60 years were examined to establish a morphological classification of the face. It is suggested that such a classification could assist facial identification by photocomparison. The selection criteria stress the importance of interassessor agreement and discrimination among feature subset units in formulating the proposed classification.

Drug and alcohol use in fatally injured drivers in Washington State

Abstract: Blood and/or urine from fatally injured drivers in Washington State were collected and tested for the presence of drugs and alcohol. Drug and/or alcohol use was a factor in 52% of all fatalities. Among single vehicle accidents, alcohol use was a factor in 61% of cases versus 30% for multiple vehicle accidents. Drugs most commonly encountered were marijuana (11%), cocaine (3%), amphetamines (2%), together with a variety of depressant prescription medications. Trends noted included an association of depressant use with higher blood alcohol levels, while marijuana use was associated with lower blood alcohol levels. Marijuana use was noted to be most prominent in the 15-30 year age group, stimulant use in the 21-40 year old group, and prescription depres- sant use was more prevelant in the 45+ age group. Drug use demographics in this population are consistent wi~ those noted in other jurisdictions.

The Incidence of Acute Cocaine or Methamphetamine Intoxication in Deaths Due to Ruptured Cerebral (Berry) Aneurysms

Abstract: Acute intoxication with either cocaine or methamphetamine may contribute to formation and rupture of a berry aneurysm by causing transient hypertension and tachycardia. We report the results of a retrospective study to determine the incidence of acute cocaine or methamphetamine intoxication in deaths due to ruptured berry aneurysm in our jurisdictions. We reviewed all deaths from ruptured cerebral aneurysms that fell within our jurisdictions during the seven years from 1 January 1987 to 31 December 1993 and found 83 cases. The mechanism of death invariably involved subarachnoid hemorrhage, although some cases also had intracerebral hemorrhage. A history of drug abuse was found in 13 cases. Toxicological analysis was performed in 39 cases. Of these methamphetamine was detected in six cases and cocaine in three cases—an incidence of 21%. (In one case both methamphetamine and cocaine were detected.) The incidence of acute cocaine intoxication in all autopsies in Jefferson County was 13.6%. The incidence of methamphetamine intoxication in all autopsies in San Diego County was 4.9%. Although the exact mechanism by which berry aneurysms form remains undetermined, research indicates that propagation and rupture of the aneurysm are aggravated by hypertension and tachycardia, both of which are pharmacologic side effects of cocaine and methamphetamine. Based on the preponderance of methamphetamine associated with deaths due to ruptured berry aneurysms it appears that methamphetamine is more toxic than cocaine, perhaps owing to the longer half-life of methamphetamine.

Validation of multiplex polymorphic STR amplification sets developed for personal identification applications.

Abstract: Polymorphic short tandem repeat (STR) loci, which typically consist of variations in the number of 3-7 base pair repeats present at a site, provide an effective means of personal identification. Typing can be accomplished by amplification of genomic DNA using the polymerase chain reaction (PCR) and locus-specific primers, separation of amplified alleles using gel electrophoresis and their display using silver staining or fluorescent detection. Primers for several STR loci can be combined in a single multiplex reaction so typing of multiple loci can be accomplished rapidly and with less DNA than required if each locus were analyzed separately. Before such muliplex systems are used in forensic or paternity applications, it is desirable that they undergo testing for their reliability. This study evaluates the performance of two STR triplex systems, one containing the loci HUMCSF1PO, HUMTPOX, and HUMTH01, and the other containing HUMHPRTB, HUMFESFPS, and HUMVWFA31. Protocols for amplification of these two triplexes, and their corresponding monoplexes, were evaluated for sensitivity of detection, resistance to changes in the annealing temperature of the amplification protocol, and the ability to identify the minority contributor in amplification of mixed samples. In addition, five laboratories determined the alleles of twenty DNA samples, each extracted by one of four different extraction methods. The results illustrate that the two STR triplex systems and the monoplex systems contained within them can be used with as little as 0.25 ng of DNA template. Both triplexes amplified with 100% success using the Perkin Elmer Model 480 thermal cycler. With the GeneAmp 9600 System, the CTT triplex amplified with 100% success and the HFv triplex in 95.6% of attempts. These experiments meet many requirements for use in validation of DNA typing systems for forensic cases and paternity identification.