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Biomedical subjects

I C Stone

Publications and source records attributed to I C Stone.

15 recordsLinked to original sources

Primer residues deposited by handguns.

There is much anecdotal information being disseminated, even offered in expert witness testimony, concerning the deposit of primer residues on the hands of persons in front of the muzzle of handguns. We present data for 9 mm and 380 Auto pistols and for a 38 caliber revolver depicting the procedure for obtaining wipings taken from targets representing the hands of a gunshot victim. These wipings from pork tissue were then analyzed for the primer residue metals antimony, barium, and lead. The data show that the two primary metals, antimony and barium, are deposited on the targets out to 4 feet for the pistols and out to three feet for the 38-caliber revolver. Testing will continue in actual cases with the gun and ammunition involved in the shooting.

Animals↗

Racial and ethnic patterns in firearms deaths.

In the United States, there is currently an epidemic of firearms violence. Among victims of this violence, there are striking racial and ethnic patterns in the manners and circumstances of death. This study was conducted to explore and quantitate some of these differences. Autopsy and investigation reports of 554 consecutive firearms deaths in Dallas County, Texas, from March 1992 to February 1993 were reviewed. Overall suicide rates by race for 1970 and 1990 were calculated. Suicide rates for blacks have increased while overall rates (all races) have decreased slightly. Large racial and ethnic differences in the homicide-suicide ratio (H:S) were found (0.42 in non-Hispanic whites; 7.44 in others) (p < 0.001). Non-Hispanic whites who committed suicide with a firearm were less likely than other groups to do so with another person present (12% non-Hispanic whites; 49% others) (p < 0.001). Blacks and Asians who committed suicide with a firearm killed another person in 67% of witnessed cases (those with another person present during the incident). Whites (Hispanics and non-Hispanics) killed another person in only 12% of witnessed firearm suicides. The data suggest that the subtypes, psychodynamics, and causes of suicide may currently differ among racial and ethnic groups. These differences should be considered in order to formulate adequate prevention strategies and to assess the suicide and homicide risk in depressed individuals. The difficulty of accurate death certification in some cases is also discussed.

Black or African American↗

Characteristics of firearms and gunshot wounds as markers of suicide.

Data from a total of 1,200 cases that the Medical Examiner of Dallas County, Texas, ruled as suicide with a firearm have been compared with the results of forensic laboratory examinations and tests; 75% are with handguns and 25% are with long guns. The incidence of suicides by gender yields 82% males and 18% females, with the most common entrance site being the head. With regard to racial distribution of persons committing suicide, > 88% are white in the study population group, which is 76% white. Data are presented for the incidence of blood detected inside and on the muzzle end of the barrel of the firearm, and for the persistence of blood inside the barrel even after the weapon was discharged to obtain test bullets. The analysis of handwipings for primer residues shows that "positive" results are obtained for approximately 50% of the revolvers and approximately 32% of the pistols when the caliber is > 22. Other projects such as transfer of gunshot residues to the hand by simply handling the weapon, the incidence of single-contact wounds in homicide versus suicide cases, and the percent of positive identification of bullets with weapons submitted are described.

Black or African American↗

Sexual assault in postmenopausal women.

OBJECTIVE: To examine patient characteristics, patterns of injury, forensic evidence, and the frequency of sexual assault in postmenopausal rape victims from 1986-1991. METHODS: Medical and forensic records were reviewed from 129 postmenopausal women (50 years of age or older) and 129 women from a comparison group (14-49 years of age) who reported having been sexually assaulted. Statistical analysis was performed by Student t test, chi 2, multiple logistic regression, or Fisher exact test. RESULTS: Postmenopausal women represented 2.2% of women reporting sexual assault in Dallas County. The postmenopausal victim was more often white (64%), whereas the younger victim was more often black (53%). Drug or alcohol use within the previous 24 hours was more common in the younger group. Trauma, in general, was common, occurring in 67% of the postmenopausal women and 71% of the younger group (P = not significant). Genital trauma was more common in the postmenopausal group (43 versus 18%; P < .001). Nearly one in three postmenopausal women had genital abrasions or edema. Almost one in five older women had genital lacerations, with one in four severe enough to require surgical repair. In contrast, the frequency of extragenital trauma was more common in younger victims (66 versus 49%; P < .01). Forensic findings were similar in both groups; however, in postmenopausal women motile spermatozoa were seen only in those examined within 6 hours of the assault. CONCLUSION: Postmenopausal women who have been sexually assaulted are more likely to sustain genital trauma than younger victims.

Adolescent↗

Interpretation of unusual wounds caused by firearms.

The interpretation of the range of fire of gunshot wounds requires coordination of information and observations from the autopsy surgeon, scene investigator, and laboratory analyst. Opinions based on incomplete information often lead to misinterpretation of the wound. The effects of interposed targets such as clothing, windows, and body parts are discussed. Case examples are given for interposed targets that cause confusing patterns and even lead to misidentification of the points of entrance and exit of the projectile in the body. The splitting of tissue in areas of bony prominence can be mistaken for evidence of discharge of a firearm at close range.

Forensic Medicine↗

Sexual assault in pregnancy.

Little is known about the acute effects of sexual assault on pregnant victims and the outcome of their gestations. A retrospective review of sexual assault victims in Dallas County from 1983-1988 revealed that 114 of 5734 (2%) were pregnant. There were 0.55 and 0.75 gravid sexual assault victims per 1000 deliveries for Dallas County and Parkland Memorial Hospital, respectively. The purposes of this study were to examine patient demographics, forensic evidence and patterns of injury in pregnant victims compared with 114 matched nonpregnant sexual assault victims, and to compare pregnancy outcome with that of the Parkland Memorial Hospital obstetric population. The typical victim was a black, parous gravida in her twenties at a mean gestational age of 15 weeks, without previous prenatal care. Vulvar (95%), oral (27%), and anal (6%) penetration were reported with similar frequency in both groups. The detection of whole and motile sperm from the vaginal specimens was similar in pregnant and nonpregnant women. Physical trauma was more common in nonpregnant victims (63 versus 43%; P less than .004), especially genital trauma (21 versus 5%; P less than .001). Injury was more common to the head and neck or extremities than to the abdomen, chest, or back in both groups. There was no difference in the pattern of trauma by gestational age, but there were no truncal injuries in women at 20 weeks' gestation or greater. There were no spontaneous abortions or deliveries within 4 weeks of the assault, but low birth weight delivery (24%) and preterm delivery (16%) were common.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Observations and statistics relating to suicide weapons.

The weapon at the scene of a suicide provides a resource in addressing such questions as frequency of blood in or on the weapon, location of the weapon with respect to the body, and evidence of firearm discharge residues on the hand. The first 195 weapons were tested for blood by a technique different from the following 202 weapons. Results were obtained which caused procedural changes in blood detection. Data are presented for frequency of blood in and on the muzzle of weapons, relative frequency of location of suicidal gunshot wound, and percent "positive" findings of gunshot residue metals on the hands. It was found that suicidal gunshot wounds were 3 times more frequent to the head than the chest, and that no significant difference was noted between males and females in this study. Scene photographs reveal that the suicide weapon is in or resting on the hand of the decedent 20% of the time with handguns and 11% of the time with long guns.

Blood↗

Gunshot wounds: visual and analytical procedures.

Visual examination of clothing and tissue from gunshot wounds provides information pertaining to the range of discharge of a firearm. Identification of powder grains or soot is evidence of close range discharge by a handgun. Analyses of tissue by EDX and FAAS technics are shown to supply corroborating data to visual examination in estimation of range. These methods are of particular value in differentiating contact and distant wounds when decomposed bodies are examined and when multiple layers of clothing are present.

Forensic Medicine↗

An experimental study of powder tattooing of the skin.

Test firings were conducted on specially prepared live rabbits to determine the approximate maximum ranges at which powder tattooing occurs for different forms of gunpowder. For .38 caliber, powder tattooing from cartridges loaded with flake powder disappears at a range of 18 to 24 in. (0.4 to 0.6 m). Powder tattooing with flattened ball powder extends to 36 in. (0.9 m), while that due to ball powder extends to 48 in. (1.2m) of range. In .22 caliber, powder tattooing was observed out to 24 in. (0.6 m) with flake powder and 18 in. (0.4 m) with flattened ball. Attempts to reproduce the animal powder tattoo patterns on paper revealed that the paper patterns are consistent with skin tattoo patterns only up to 18 in (0.4 m) of range.

Animals↗

Contaminants in illicit amphetamine preparations.

Samples from illicit preparations of amphetamine and methamphetamine were investigated by combined gas chromatography-mass spectrometry (GC/MS) to detect and identify contaminants, excipients, and by-products from manufacture. In addition, these samples were subjected to energy-dispersive X-ray (EDX), and it was determined that the preparations of these compounds were made in the present of zinc, probably as a reductant. In addition to identifying polycondensation products from these preparations, the illicit origin of amphetamine-type drugs can generally be determined by the detection of contaminants and by-products present in submitted samples. Thus, a multidisciplinary analytical approach yields data of potential value for comparative examinations and possibly for legal purposes.

Amphetamines↗