Macromorphological findings in cases of death in water: a critical view on "drowning signs".

Death in water is a challenging issue in forensic pathology since from natural death to homicide all circumstances of death in water are conceivable. Therefore, the correct interpretation of all abnormal autopsy findings is important. In order to determine a death by drowning, numerous internal and external signs of drowning are already described. However, these are supposed to be influenced by various factors reducing their significance and evidence. Moreover, the autopsy of water corpses often reveals further pathological findings that should not be underestimated for determining the cause of death. The aim of this study was to set frequencies of the observed drowning signs in context to the forensic literature and to identify possible influencing factors. In this study, we observed that pathological organ changes of the cardiovascular system were significantly more common in corpses after shortened (atypical) drowning processes than in classical drowned victims. Furthermore only a complete formation of external foam, immediately after the corpse's recovery, was exclusively found in drowning victims. All other drowning signs were either also observed in non-drowning deaths in water or no information could be provided with reasonable assurance. In addition, many of the examined drowning signs were negatively affected by prolonged postmortem intervals, putrefaction, or resuscitation attempts. It can be concluded from our analysis that morbidity is an important factor in deaths in water. Morbidity can support a death by drowning in case of incidents in water. For the examined drowning signs, no high diagnostic certainty could be observed. Nevertheless, these findings can increase their diagnostic value-if forensic physicians take influencing factors into consideration.

Energy-dependent expansion of .177 caliber hollow-point air gun projectiles.

Amongst hundreds of different projectiles for air guns available on the market, hollow-point air gun pellets are of special interest. These pellets are characterized by a tip or a hollowed-out shape in their tip which, when fired, makes the projectiles expand to an increased diameter upon entering the target medium. This results in an increase in release of energy which, in turn, has the potential to cause more serious injuries than non-hollow-point projectiles. To the best of the authors' knowledge, reliable data on the terminal ballistic features of hollow-point air gun projectiles compared to standard diabolo pellets have not yet been published in the forensic literature. The terminal ballistic performance (energy-dependent expansion and penetration) of four different types of .177 caliber hollow-point pellets discharged at kinetic energy levels from approximately 3 J up to 30 J into water, ordnance gelatin, and ordnance gelatin covered with natural chamois as a skin simulant was the subject of this investigation. Energy-dependent expansion of the tested hollow-point pellets was observed after being shot into all investigated target media. While some hollow-point pellets require a minimum kinetic energy of approximately 10 J for sufficient expansion, there are also hollow-point pellets which expand at kinetic energy levels of less than 5 J. The ratio of expansion (RE, calculated by the cross-sectional area (A) after impact divided by the cross-sectional area (A 0) of the undeformed pellet) of hollow-point air gun pellets reached values up of to 2.2. The extent of expansion relates to the kinetic energy of the projectile with a peak for pellet expansion at the 15 to 20 J range. To conclude, this work demonstrates that the hollow-point principle, i.e., the design-related enlargement of the projectiles' frontal area upon impact into a medium, does work in air guns as claimed by the manufacturers.

Penetrating chest trauma caused by a blank cartridge actuated rubber ball projectile: case presentation and ballistic investigation of an uncommon weapon type.

Recently, an increasing number of an uncommon weapon type based on a caliber 6-mm Flobert blank cartridge actuated revolver which discharges 10-mm-diameter rubber ball projectiles has been confiscated by police authorities following criminal offenses. A recent trauma case presenting with a penetrating chest injury occasioned an investigation into the basic ballistic parameters of this type of weapon. Kinetic energy E of the test projectiles was calculated between 5.8 and 12.5 J. Energy density ED of the test projectiles was close to or higher than the threshold energy density of human skin. It can be concluded that penetrating skin injuries due to free-flying rubber ball projectiles discharged at close range cannot be ruled out. However, in case of a contact shot, the main injury potential of this weapon type must be attributed to the high energy density of the muzzle gas jet which may, similar to well-known gas or alarm weapons, cause life-threatening or even lethal injuries.

Modeling internal ballistics of gas combustion guns.

Potato guns are popular homemade guns which work on the principle of gas combustion. They are usually constructed for recreational rather than criminal purposes. Yet some serious injuries and fatalities due to these guns are reported. As information on the internal ballistics of homemade gas combustion-powered guns is scarce, it is the aim of this work to provide an experimental model of the internal ballistics of these devices and to investigate their basic physical parameters. A gas combustion gun was constructed with a steel tube as the main component. Gas/air mixtures of acetylene, hydrogen, and ethylene were used as propellants for discharging a 46-mm caliber test projectile. Gas pressure in the combustion chamber was captured with a piezoelectric pressure sensor. Projectile velocity was measured with a ballistic speed measurement system. The maximum gas pressure, the maximum rate of pressure rise, the time parameters of the pressure curve, and the velocity and path of the projectile through the barrel as a function of time were determined according to the pressure-time curve. The maximum gas pressure was measured to be between 1.4 bar (ethylene) and 4.5 bar (acetylene). The highest maximum rate of pressure rise was determined for hydrogen at (dp/dt)max = 607 bar/s. The muzzle energy was calculated to be between 67 J (ethylene) and 204 J (acetylene). To conclude, this work provides basic information on the internal ballistics of homemade gas combustion guns. The risk of injury to the operator or bystanders is high, because accidental explosions of the gun due to the high-pressure rise during combustion of the gas/air mixture may occur.

Ballistic parameters and trauma potential of carbon dioxide-actuated arrow pistols.

Medical literature abounds with reports of injuries and fatalities caused by arrows and crossbow bolts. Crossbows are of particular forensic and traumatological interest, because their mode of construction allows for temporary mechanical storage of energy. A newly developed type of pistol (Arcus Arrowstar), which belongs to the category of air and carbon dioxide weapons, discharges arrow-shaped bolts actuated by carbon dioxide cylinders. As, to the best of the authors' knowledge, literature contains no information on this uncommon subclass of weapons it is the aim of this work to provide the experimental data and to assess the trauma potential of these projectiles based on the ascertained physical parameters. Basic kinetic parameters of these carbon dioxide-actuated bolts (velocity v = 39 m/s, energy E = 7.2 J, energy density E' = 0.26 J/mm(2)) are similar to bolts discharged by pistol crossbows. Subsequent firing resulted in a continuous and fast decrease in kinetic energy of the arrows. Test shots into ballistic soap blocks reveal a high penetration capacity, especially when compared to conventional projectiles of equal kinetic energy values (like, e.g., airgun pellets). To conclude, these data demonstrate the high efficiency of arrow-shaped projectiles, which are also characterized by a high cross-sectional density (ratio of mass to cross-sectional area of a projectile).

Subcaliber discarding sabot airgun projectiles.

Medical literature abounds with reports on injuries and fatalities caused by airgun projectiles. While round balls or diabolo pellets have been the standard projectiles for airguns for decades, today, there are a large number of different airgun projectiles available. A very uncommon--and until now unique--discarding sabot airgun projectile (Sussex Sabo Bullet) was introduced into the market in the 1980s. The projectile, available in 0.177 (4.5 mm) and 0.22 (5.5 mm) caliber, consists of a plastic sabot cup surrounding a subcaliber copper-coated lead projectile in typical bullet shape. Following the typical principle of a discarding sabot projectile, the lightweight sabot is supposed to quickly loose velocity and to fall to the ground downrange while the bullet continues on target. These sabot-loaded projectiles are of special forensic interest due to their non-traceability and ballistic parameters. Therefore, it is the aim of this work to investigate the ballistic performance of these sabot airgun projectiles by high-speed video analyses and by measurement of the kinetic parameters of the projectile parts by a transient recording system as well as observing their physical features after being fired. While the sabot principle worked properly in high-energy airguns (E > 17 J), separation of the core projectile from the sabot cup was also observed when discharged in low-energy airguns (E < 7.5 J). While the velocity of the discarded Sussex Sabo core projectile was very close to the velocity of a diabolo-type reference projectile (RWS Meisterkugel), energy density was up to 60 % higher. To conclude, this work is the first study to demonstrate the regular function of this uncommon type of airgun projectile.

["Piggyback" shot: ballistic parameters of two simultaneously discharged airgun pellets]. / Der "Huckepack"-Schuss: ballistische Parameter doppelt geladener Luftgewehr-Projektile.

Green and Good reported an uncommon case of homicide committed with an air rifle in 1982 (Am. J. Forensic Med. Pathol. 3: 361-365). The fatal wound was unusual in that two airgun pellets were loaded in so-called "piggyback" fashion into a single shot air rifle. Lack of further information on the ballistic characteristics of two airgun pellets as opposed to one conventionally loaded projectile led to this investigation. The mean kinetic energy (E) of the two pellets discharged in "piggyback" fashion was E = 3.6 J and E = 3.4 J, respectively. In comparison, average kinetic energy values of E = 12.5 J were calculated for conventionally discharged single diabolo pellets. Test shots into ballistic soap confirmed the findings of a single entrance wound as reported by Green and Good. While the ballistic background of pellets discharged in "piggyback" fashion could be clarified, the reason behind this mode of shooting remains unclear.

Ballistic parameters of .177 (4.5 mm) caliber plastic-sleeved composite projectiles compared to conventional lead pellets.

The capability of conventional air gun lead pellets (diabolo pellets) to cause severe injuries or fatalities even at low kinetic energy levels is well documented in medical literature. Modern composite hunting pellets, usually a metal core (made of steel, lead, zinc, or a zinc and aluminum alloy) encased in a plastic sleeve, are of special forensic and traumatological interest. These projectiles are advertised by the manufacturers to discharge at higher velocities than conventional air gun pellets, thus generating very high tissue-penetrating capabilities. Lack of experimental data on these uncommon air gun projectiles induced this work. Ballistic parameters of 12 different caliber .177 (4.5 mm) composite pellets, discharged from two spring-piston air guns (Weihrauch HW 35, Webley CUB) and three pneumatic air guns (Walther LGR, Walther LG400, Walther LP300), were investigated using a ballistic speed measurement system and compared to a conventional diabolo pellet (RWS Meisterkugel) as reference projectile. Although overall results were inconsistent, for some projectile-weapon combinations (particularly spring-piston air guns), a significant change of the kinetic energy (-53 up to +48 %) to the reference projectile was observed. The data provided in this work may serve as a basis for forensic investigation as well as traumatological diagnosis and treatment of injuries caused by these uncommon projectiles.

Nail projectiles propelled by a mason's lacing cord: an experimental approach.

The recent clinical observation of two unintentional penetrating ocular and cerebral injuries due to 90-mm construction nails gave occasion to an experimental study to check the alleged trauma mechanism for plausibility. Both casualties reported that they had attached a mason's lacing cord to the masonry using a nail as anchoring when suddenly the nail was yanked from its moorings and propelled like a missile by the overstretched lacing cord. As to the best of the authors' knowledge, this mechanism of injury has not yet been reported in any of the literature; it was the aim to find an experimental approach to review the plausibility of the alleged sequence of events leading to the accidents. The tensile strength at break and strain at break of different mason's lacing cords (diameter of 1 and 2 mm) were measured according to DIN EN ISO 2062 by using a tensile testing machine. Based on the maximum spring energy of the lacing cords, which was determined 174.9 J for the 1-mm cord (length 10 m) and 747.4 J for the 2-mm cord (length 10 m), the maximum possible velocity of the nails as projectiles was calculated to be 243.5 m/s for the 1-mm cord and 503.4 m/s for the 2-mm cord. The critical elongation a cord of a certain length has to be stretched to deliver enough kinetic energy to a 90-mm nail to surpass the threshold velocity for skin penetration, which was investigated by Sellier (1977) to be approximately 18 m/s, was also calculated. To conclude, the energy delivered by the cords is high enough to surpass the rather low threshold velocity of nails. The details of how these accidents occurred, which seemed questionable at first, can be reasonably explained by trauma biomechanics.

Ballistic parameters and trauma potential of pistol crossbows.

Hand-held pistol crossbows, which are smaller versions of conventional crossbows, have recently increased in popularity. Similar to conventional crossbows, life threatening injuries due to bolts discharged from pistol crossbows are reported in forensic and traumatological literature. While the ballistic background of conventional crossbows is comprehensively investigated, there are no investigations on the characteristic ballistic parameters (draw force, potential energy, recurve factor, kinetic energy, and efficiency) of pistol crossbows. Two hand-held pistol crossbows (Barnett Commando and Mini Cross Bow, rated draw force 362.9 N or 80 lbs) were tested. The maximum draw force was investigated using a dynamic tensile testing machine (TIRAtest 2705, TIRA GmbH). The potential energy was determined graphically by polynomial regression as area under the force-draw curve. External ballistic parameters of the bolts discharged from pistol crossbows were measured using a redundant ballistic speed measurement system (Dual-BMC 21a and Dual-LS 1000, Werner Mehl Kurzzeitmesstechnik). The average maximum draw force was 190.3 and 175.6 N for the Barnett and Mini Cross Bow, respectively. The corresponding total energy expended was 10.7 and 11 J, respectively. The recurve factor was calculated to be 0.705 and 1.044, respectively. Average bolt velocity was measured 43 up to 52 m/s. The efficiency was calculated up to 0.94. To conclude, this work provides the pending ballistic data on this special subgroup of crossbows which operate on a remarkable low kinetic energy level. Furthermore, it demonstrates that the nominal draw force pretended in the sales brochure is grossly exaggerated.

[The medical post-mortem examination - step by step]. / Die ärztliche Leichenschau ­ Schritt für Schritt.

The physician has to make numerous and legally far-reaching determinations in the course of the post-mortem examination. These can have considerable consequences for relatives and, moreover, for society. Therefore, the correct performance of post-mortem examinations and the correct evaluation of the findings is an extremely responsible task that every physician should master.

Temporary cavity created by free-flying projectiles propelled from a powder-actuated nail gun.

Nails and driving pins discharged from powder-actuated fastening tools bear some special ballistic characteristics. Compared to the usual pistol or revolver projectiles, the sectional density (S) of fastening pins is extremely high. The general prevailing opinion is that the kinetic energy delivered by fastening tools is not high enough to cause a temporary cavity. Therefore, it was the aim of this study to investigate the wound morphology due to fastening bolts discharged from a powder-actuated direct-acting nail gun (where, in contrast to modern piston-type tools, the expanding gases act directly on the fastener) using ballistic soap blocks as simulants. For test shots, a direct-acting powder-actuated nail gun which features three interchangeable barrels (caliber (cal.) 6, 8, and 10 mm) was used. The average kinetic energy was 537, 532, and 694 J for the 6-, 8-, and 10-mm cal. bolts, respectively. Test shots on the ballistic soap blocks demonstrated that free-flying projectiles discharged from direct-acting fastening tools are able to create a temporary cavity.

When backyard fun turns to trauma: risk assessment of blunt ballistic impact trauma due to potato cannons.

Although potato cannons are an area of great interest among internet users, they are almost completely unknown in the medical community. These simple ballistic devices are made from plastic plumbing pipes and are powered with propellant gas from aerosol cans. By combustion of the gas-oxygen mixture, a high pressure is produced which propels the potato chunks through the barrel. It is the aim of this study to investigate the hazardous potential of these shooting devices. Test shots were performed using three illegally manufactured potato cannons that were confiscated by police authorities. Velocity, impulse, kinetic energy, and energy density were calculated. The risk of head and chest injuries was investigated by using Sturdivan's Blunt Criterion (BC), an energy based five parametric trauma model assessing the vulnerability to blunt weapons, projectile impacts, and behind-body-armor exposures. The probability of lethality due to blunt impact trauma to the chest was assessed using Sturdivan's lethality model. For potential head impacts, all test shots far exceeded the critical BC (head) value which corresponds to a 50% risk of skull fracture. The risk of injury with regard to chest impacts was similar. All but two test shots far exceeded the critical BC (chest) value corresponding to a 50% risk of sustaining a thoracic skeletal injury of Abbreviated Injury Scale 2 or 3. The probability of a lethal injury due to blunt chest impact was as high as 20%. To conclude, this work demonstrates that potato cannons should be considered dangerous weapons rather than as toys used by adventurous adolescents.

Ballistic parameters and trauma potential of direct-acting, powder-actuated fastening tools (nail guns).

Since their introduction in the 1950s in the construction and building trade, powder-actuated fastening tools (nail guns) are of forensic and traumatological importance. There are countless reports on both accidental and intentional injuries and fatalities caused by these tools in medical literature. While the ballistic parameters of so-called low-velocity fastening tools, where the expanding gases act on a captive piston that drives the fastener into the material, are well known, ballistic parameters of "high-velocity" tools, which operate like a firearm and release the energy of the propellant directly on the fastener, are unknown. Therefore, it was the aim of this work to investigate external ballistic parameters of cal. 9 and 6-mm fastening bolts discharged from four different direct-acting nail guns (Type Ideal, Record Piccolo S, Rapid Hammer R300, Titan Type 1). Average muzzle velocity ranged from 400 to 580 m/s, while average kinetic energy of the projectiles ranged from 385 to 547 J. Mean energy density of the projectiles ranged from 9 to 18 J/mm(2). To conclude, this work demonstrates that the muzzle velocity of direct-acting high-velocity tools is approximately five times higher than the muzzle velocity of piston-type tools. Hence, the much-cited comparison to the ballistic parameters of a cal. 22 handgun might be understated and a comparison to the widespread and well-known cal. 9 mm Luger might be more appropriate.

[Reconstruction of sexual offences--forensic aspects of sperm traces]. / Tatrekonstruktion bei Sexualdelikten--forensische Aspekte von Spermaspuren.

The investigation of sexual offences is a real challenge, as the injuries are often unspecific or faint and may sometimes be missing completely. Evidence recovery and analysis as well as the statements of the victims and suspects are therefore of vital importance. In both presented cases, the results of trace evidence analysis were basically consistent with a sexual assault, but the victims' statements regarding the course of events and the pattern of traces showed severe discrepancies.

[Vital animal predation of the genital region caused by a mongrel dog]. / Vitaler Genitalfrass durch einen Mischlingshund.

A 79-year-old man, who was in a helpless situation due to cardiac decompensation, suffered dog bite injuries on the left thigh and in the genital region while still alive. Two extensive soft-tissue defects with contused and bruised wound edges were surrounded by multiple slit-like skin lesions. The outer genitals were almost completely missing. Because of surgical emergency treatment, molecular biological investigations were no longer possible. Therefore, the cause of the bite injuries had to be determined solely on the basis of the documented morphology of the wounds.

[Lethal intoxication while driving a car]. / Letale Intoxikation im fahrenden PKW.

This report concerns a passenger car crash, which at first looked like a case of multiple trauma resulting in the death of the pinned-in driver. Conspicuous was a cuff that had been applied to the left forearm. No significant injuries could be determined during the autopsy of the corpse. The forensic toxicology results showed lethal toxic concentrations of the painkiller pethidine, which suggests that the driver had applied a lethal dose of the medication immediately before the collision as part of a complex suicide.

Urinary bladder volume measured in whole-body CT scans is a useful marker for alcohol intoxication.

PURPOSE: The aim of this study was to investigate whether urinary bladder volume (UBV) and blood alcohol concentration (BAC) correlate in a cohort of emergency trauma patients. Furthermore, the feasibility of semi-automated 3D-CT volumetry for urinary bladder volumetry calculations in whole-body CT examinations was elucidated. MATERIAL AND METHODS: Whole-body CT scans of 831 individuals treated in the emergency department with suspected multiple injuries were included. Manual 3D-CT volumetry of the urinary bladder was performed and the mechanism of injury, patient demographics, BAC, serum creatinine, and hematocrit were retrospectively analyzed. Semi-automated calculation of UBV was performed in 30 patients. Statistical analysis included ROC analysis to calculate cut-off values, sensitivity, and specificity. The Mann-Whitney test and Spearman's correlation coefficient were used to detect significant correlations between UBV and BAC. RESULTS: Manual 3D-CT volumetry showed maximum sensitivity and specificity with a cut-off value for urinary bladder volume of 416.3 mL (sensitivity 50.9%; specificity 76.3%; AUC 0.678). With a cut-off value of 4.2 mL/µmol for the creatinine quotient (quotient of serum creatinine and UBV), the sensitivity was 64.2% (specificity 67.0%; AUC 0.681). Semi-automated 3D-CT volumetry resulted in lower UBV values compared to those obtained with manual 3D-CT volumetry. CONCLUSION: Semi-automated 3D-CT volumetry is a reliable method to quantify UBV. UBV correlates with positive BAC results. A UBV above 416 mL seen on an initial whole-body CT must raise suspicion of alcohol intoxication. The creatinine quotient is an even more sensitive and specific parameter for the detection of alcohol intoxication.

Ethanol and ethyl glucuronide urine concentrations after ethanol-based hand antisepsis with and without permitted alcohol consumption.

BACKGROUND: During hand antisepsis, health care workers (HCWs) are exposed to alcohol by dermal contact and by inhalation. Concerns have been raised that high alcohol absorptions may adversely affect HCWs, particularly certain vulnerable individuals such as pregnant women or individuals with genetic deficiencies of aldehyde dehydrogenase. METHODS: We investigated the kinetics of HCWs' urinary concentrations of ethanol and its metabolite ethyl glucuronide (EtG) during clinical work with and without previous consumption of alcoholic beverages by HCWs. RESULTS: The median ethanol concentration was 0.7 mg/L (interquartile range [IQR], 0.5-1.9 mg/L; maximum, 9.2 mg/L) during abstinence and 12.2 mg/L (IQR, 1.5-139.6 mg/L; maximum, 1,020.1 mg/L) during alcohol consumption. During abstinence, EtG reached concentrations of up to 958 ng/mL. When alcohol consumption was permitted, the median EtG concentration of all samples was 2,593 ng/mL (IQR, 890.8-3,576 ng/mL; maximum, 5,043 ng/mL). Although alcohol consumption was strongly correlated with both EtG and ethanol in urine, no significant correlation for the frequency of alcoholic hand antisepsis was observed in the linear mixed models. CONCLUSIONS: The use of ethanol-based handrub induces measurable ethanol and EtG concentrations in urine. Compared with consumption of alcoholic beverages or use of consumer products containing ethanol, the amount of ethanol absorption resulting from handrub applications is negligible. In practice, there is no evidence of any harmful effect of using ethanol-based handrubs as much as it is clinically necessary.

Hemorrhages of the tongue in the postmortem diagnostics of strangulation.

Hemorrhages of the tongue can be useful for the diagnosis in cases of lethal neck compression. The reported frequencies of tongue bleedings in the literature in cases of suicidal hanging range from 0 to 14% and in homicidal strangulation (str.) from 5 to 37%. This study gives a summary of the incidence and intensity of tongue bleedings in cases of homicidal str. by ligature, manual str., suicidal str. by ligature and suicidal hanging. In 25% of all homicides significant or massive hemorrhages of the tongue were detected. In contrast to this, in suicidal hanging the tongue was unaffected in 95%. The causes of massive hemorrhages here (2%) could be explained by an "abnormal" position of the loop.