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Abstract: In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 bullets and 2461 cartridge cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard. [Copyright &y& Elsevier]

Abstract: The National Institute of Standards and Technology (NIST) in collaboration with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has developed the Standard Reference Material (SRM) 2460 Bullets and 2461 Casings. NIST has also developed a 2D and 3D Topography Measurement and Correlation System for ballistics signature measurements. This system includes stylus instruments and a confocal microscope for 2D and 3D topography measurements, and a 2D and 3D topography correlation program developed by NIST. NIST and ATF are proposing to establish a National Ballistics Measurement Traceability and Quality System using these materials. In this paper, basic concepts and specific requirements for establishing ballistics measurement traceability are introduced; three key issues are discussed that include: (1) establishing a reference standard; (2) establishing an unbroken chain of calibrations; and (3) evaluating measurement uncertainty for both the geometrical topography measurements and the optical image correlations of the ballistics signatures. [Copyright &y& Elsevier]

We explore the impact of information from ballistics imaging hit reports on the investigation into violent crimes. Ballistics imaging hits link two crimes involving the same firearm by forensically matching tool marks on the fired bullets or cartridge cases. Interview data collected from detectives who received a hit report were used to explore the relationship between the presence of a hit report and outcomes in 65 gun-related violent crime investigations in nine U.S. police agencies. Findings indicate hit reports rarely contribute to identification, arrest, charging, or sentencing of suspects, because of delays in producing hit reports. On average, hit reports were completed 181.4 days after the focal crime. This delay forces investigations to proceed without the benefit of information from ballistics analysis. Additionally, hit reports rarely contained detailed information that was immediately useful to investigators. Instead, hit reports required additional research by the investigator to unlock useful information. [ABSTRACT FROM AUTHOR]

This ballistics study examines whether saline breast implants can decrease tissue penetration in firearm injuries. We hypothesize that the fluid column within a saline breast implant can alter bullet velocity and/or bullet pattern of mushrooming. The two experimental groups included saline implants with 7.4 cm projection and a no implant group. The experimental design allowed the bullet to pass-through an implant and into ballistics gel (n = 10) or into ballistics gel without passage through an implant (n = 11). Shots that passed through an implant had 20.6% decreased penetration distance when compared to shots that did not pass-through an implant; this difference was statistically significant (31.9 cm vs. 40.2 cm, p < 0.001). Implant group bullets mushroomed prior to gel entry, but the no implant group mushroomed within the gel. Bullet passage through a saline breast implant results in direct bullet velocity reduction and earlier bullet mushrooming; this causes significantly decreased ballistics gel penetration. [ABSTRACT FROM AUTHOR]

Fired bullets and ejected cartridge cases have unique ballistics signatures left by the firearm. By analyzing the ballistics signatures, forensic examiners can trace these bullets and cartridge cases to the firearm used in a crime scene. Current automated ballistics identification systems are primarily based on image comparisons using optical microscopy. The correlation accuracy depends on image quality which is largely affected by lighting conditions. Because ballistics signatures are geometrical micro-topographies by nature, direct measurement and correlation of the surface topography is being investigated for ballistics identification. A Two-dimensional and Three-dimensional Topography Measurement and Correlation System was developed at the National Institute of Standards and Technology for certification of Standard Reference Material 2460/2461 bullets and cartridge cases. Based on this system, a prototype system for bullet signature measurement and correlation has been developed for bullet signature identifications, and has demonstrated superior correlation results [ABSTRACT FROM AUTHOR]

Forensic science plays a critical role in the United States criminal legal system. For decades, many featurebased fields of forensic science, such as firearm and toolmark identification, developed outside the scientific community’s purview. The results of these studies are widely relied on by judges nationwide. However, this reliance is misplaced. Black-box studies to date suffer from inappropriate sampling methods and high rates of missingness. Current black-box studies ignore both problems in arriving at the error rate estimates presented to courts. We explore the impact of each type of limitation using available data from blackbox studies and court materials. We show that black-box studies rely on unrepresentative samples of examiners. Using a case study of a popular ballistics study, we find evidence that these nonrepresentative samples may commit fewer errors than the wider population from which they came. We also find evidence that the missingness in black-box studies is non-ignorable. Using data from a recent latent print study, we show that ignoring this missingness likely results in systematic underestimates of error rates. Finally, we offer concrete steps to overcome these limitations. Supplementary materials for this article are available online. [ABSTRACT FROM AUTHOR]

Examines the impact of ballistics imaging technology on the productivity of the Boston Police Department's Ballistic Unit. Value of ballistics imaging technology in law enforcement; Analysis of time series data with the use of negative binomial regression models; Results of cost-effectiveness estimates and qualitative evidence.

A review of the literature concerning the fate and behavior of gunshot residue ( GSR) is presented. A number of concomitant parameters including firearm and ammunition type, plume and GSR material characteristics, travel distances, chemical composition and GSR morphology are critically discussed in relation to their effects on the distribution and deposition, transfer and persistence processes of GSR. The underlying mechanisms associated with such processes are also considered. Knowledge of these processes on GSR materials could provide valuable information concerning scene preservation and subsequent forensic sampling. The number of GSR particles deposited can vary significantly with each firearm discharge, highlighting the potential to produce distinctive data in each individual case. With the continual development and compositional changes of new ammunition types, further evaluation of the effect these processes may have on GSR evidence and their possible influence on the interpretation of the analytical results should be given due consideration. [ABSTRACT FROM AUTHOR]

Damage produced by high-speed projectiles on organic tissue will depend on the physical properties of the tissues. Conditioning organic tissue samples to human core body temperature (37°C) prior to conducting ballistic experiments enables their behavior to closely mimic that of living tissues. To minimize autolytic changes after death, the tissues are refrigerated soon after their removal from the body and re-heated to 37°C prior to testing. This research investigates whether heating 50-mm-cube samples of porcine liver, kidney, and heart to 37°C for varying durations (maximum 7 h) can affect the penetration response of a high-speed, steel sphere projectile. Longer conditioning times for heart and liver resulted in a slight loss of velocity/energy of the projectile, but the reverse effect occurred for the kidney. Possible reasons for these trends include autolytic changes causing softening (heart and liver) and dehydration causing an increase in density (kidney). [ABSTRACT FROM AUTHOR]

Penetrating injuries of the heart, named penetrating cardiac injury (PCI), may cause hemorrhagic shock as well as cardiac tamponade, leading to death if not treated immediately. This systematic review aims to highlight the main aspects of penetrating cardiac injuries after firearm wounds. The cases of 39 subjects (age 37.05 + 15.4) were selected (6 fatal cases). Specifically, 4/39 cases involved subjects under 18 y.o.; analyzing the entrance wound, in 30/39 cases it was located in the anterior chest, 4/39 in the posterior chest, 3/39 in the shoulder/axilla area, 1/39 in the neck, and 1/39 in the pelvis (gluteus). The exit wound was found in only 3/39 cases. Several factors may influence the prognosis: firstly, prompt intervention represents a crucial point, then considering the complications related to PCI, the most important are myocardial infarction, and projectile migration with embolization. The mortality rate is related to: (1) area and severity of the heart injury; (2) duration of transport and intervention; (3) contemporary lesion to other organ/s; (4) the quantity of blood lost; (5) and presence/absence of cardiac tamponade. Based on these findings, a correct approach in the management of PCI may be considered important from a forensic point of view, both as regards to medical liability and from the trial perspective. [ABSTRACT FROM AUTHOR]

Firearm and ballistics in an important area in forensic investigation. Among three ballistics, terminal ballistics plays a vital role in to solve the mystery in crime scenes. The present experimental study is aimed to study the damage pattern caused on Malaysian made hollow blocks by using various firearm. For the experimental study, firearms viz. 0.38 revolver, 9mm submachine gun, 9 mm semi auto pistol, 5.56 mm rifle and 7.62 mm rifle were used with varying ranges. The shooting experiment was conducted at Sungai Buloh shooting range by trained firearms experts, Polis Di Raja Malaysia, Bukit Aman. Kuala Lumpur. The entry and exit damages were analyzed and the result of the investigation provided promising result in determining the type of firearm and other useful information. The entry damages are found to be comparatively smaller than the exit damages in the hollow blocks. The long arms caused more damages on the hollow blocks comparatively than hand arms. [ABSTRACT FROM AUTHOR]

Projectile components that are traditionally radiolucent can be of considerable importance in determination of weapon type and caliber, but they are often missed on evaluation of postmortem radiographs. We hypothesized that these components would be significantly better visualized by evaluation of computed tomography (CT) scans compared to the practice standard of radiography alone. In this project, potentially radiolucent projectile components were both pulled apart and fired, and the radiolucent components were recovered. These components were embedded in blocks of ballistics gelatin and were imaged using both radiography and CT. The scans were evaluated by three blinded, board‐certified radiologists for the presence/absence of projectile components and true‐negative regions in each block. If a radiologist indicated visualization of a projectile component, they were further requested to describe their observation. It was found that traditionally radiolucent projectile components are not significantly more often identified on CT scans than radiography (p < 0.05). [ABSTRACT FROM AUTHOR]

Abstract Background The determination of the shooting distance using gunshot residue (GSR) analysis is crucial in the investigation and reconstruction of firearm-related crimes. However, the conventional chemographic method for GSR analysis is destructive and has limited sensitivity and selectivity. While the spectroscopic method has potential in GSR analysis for crime investigation, there is a current lack of consistency in the spectroscopic results obtained for shooting distance estimation via GSR analysis. Addressing such limitations will enhance the forensic capabilities of law enforcement and provide an added advantage to crime laboratories during an investigation. It will also reinforce the use of such spectroscopic data in a criminal investigation. Main text We obtained all peer-reviewed articles relevant to shooting distance estimation from searching Scopus, Web of Science, PubMed, and Google Scholar databases. We specifically searched the databases using the keywords “shooting distance,” “range of fire,” “gunshot residue,” “firearm discharge residue,” and “firearm-related crime” and obtained 3811 records. We further filtered these records using a combination of two basic keywords “gunshot residue” and “shooting distance estimations” yielding 108 papers. Following a careful evaluation of the titles, abstracts, and full texts, 40 original peer-reviewed articles on shooting distance estimation via GSR analysis were included in the study. The forgoing included additional sources (n = 5) we obtained from looking through the reference lists of the forensic articles we found. Short conclusion This paper discusses the current scope of research concerning the chemographic and spectroscopic analysis of GSR for shooting distance estimation. It also examines the challenges of these techniques and provides recommendations for future research.

Law enforcement agencies routinely sample for gunshot residue (GSR) by bulk techniques and often submit swabs taken from other surfaces besides the hands of the suspect shooter. This study aims to establish the prevalence of antimony, barium, and lead on normally handled automobile surfaces by graphite furnace atomic absorption analysis. No positives were determined on 50 sampled automobile surfaces above cutoff (positive) from background levels. Transfers of GSR particles from shooter hands to automobile surfaces were found to potentially allow for positive GSR determinations, but such transfers seem to be dependent on the shooting conditions and length of GSR exposure. We determined that our bulk analysis method yields an overall 87.94 ± 5.52% extraction efficiency from cotton swabs, while the LOQ determinations strengthening the fact that bulk analysis methods are valid and valuable tools for GSR investigations. [ABSTRACT FROM AUTHOR]

Examines the fracture patterning of blunt force and ballistics trauma to the cranial vault. Variables examined in Contingency tables and Pearson's Chi-Square; Calculation of Pearson's correlation coefficient in determining the degree of association between variables; Discussion on the effects of intercranial pressure on the pattern of skull fractures.

Reports on the development of a bullet signature measurement system based on a stylus instrument of the National Institute of Standards and Technology in the United States. Goal for the support of the National Integrated Ballistics Information Network; Set of digitized bullet signatures profiled from master bullets; Control of the tool path to qualify bullet signature differences.

TASER weapons, classified as Conducted Energy Weapons (CEWs) are used by law enforcement as electrical, non-lethal weapons. A CEW's long distance method of deployment launches two barbed probes that embed into the target, before electricity is cycled from one probe to the other. The resulting muscle contractions help incapacitate the intended target. Currently, there is no research on the accuracy of variability of CEW probe spread in determining the distance of the shooter. Thus, in this study, a method of distance determination for TASER models X26P, X2, and TASER 7 was established to help estimate the relative locations of individuals during crime scene reconstruction. Each of four probe cartridge types were launched for six repetitions towards vertical cardboard targets from three different distances (n = 72). The probe spread on the targets was measured for each cartridge and plotted against CEW-To-Target (CTT) distance. Linear regression trendlines and standard deviations were generated for each cartridge type. Results demonstrated probe spread distances to be proportional to probe launch angles, and greater CTT distances resulted in greater standard deviation. Standard error of the estimate was calculated for all four linear regression equations and their ability to predict CTT distance when given probe spread measurements. The mean standard error values appeared acceptable for the X2 (0.460 m), TASER 7 CQ (0.273 m), and X26P (0.322 m) CEW models, while the mean error calculated for the TASER 7 Standoff model (0.846 m) was considerably greater. We expect our findings will help establish a reliable method of distance determination for CEWs, and perhaps with a larger sample size, more thoroughly examine the accuracy of the linear regression equations. CEW distance determination has the potential to provide support in contextualizing crime scene reconstruction with further research. By providing distance estimations alongside a standardized guide of error allowance, it would be possible to induce how far apart individuals were at the time a CEW was fired, within the calculated window of deviation, and in a statistical degree of confidence. [ABSTRACT FROM AUTHOR]

From forensic point of view, it is important to clarify the condition whether ricochet or perforate for a bullet fired toward the automobile windshield. The purpose of this study was to specify the critical angle at which the ricochet of the fired bullet takes place. To estimate the result of firing, a rigid-body dynamics simulation of the bullet together with the test-firing using .38 CAL. LRN bullet was examined. It was found both from numerical simulation and firing test that when the incidence angle is <45°, a complete perforation of the windshield was observed, whereas the bullet ricocheted remaining a characteristic damage on the windshield when the incidence angle is >60°. To measure the static failure resistance of various windshields, static indentation test was also examined. [ABSTRACT FROM AUTHOR]

Presents the study of the technological innovations for less-lethal kinetic energy munitions used in law enforcement in the U.S. Examinations taken to determine energy per unit area required to penetrate various regions of the body; Used of eight unembalmed postmortem human specimens in the testing experiment; Evaluation on the conducted test results.

Forensic ballistics is the study of bullet trajectory and consists of determining gunshot residue ( GSR) to identify bullet holes. Among several highly sensitive methods, atomic absorption spectrophotometry ( AAS) is employed to analyze GSR in the laboratory. However, it is sometimes necessary to identify bullet holes immediately at a crime scene. The purpose of this examination was to determine whether the use of the field test Bullet Hole Testing Kit 3 ( BTK3) on a suspected bullet hole would influence the outcome of AAS-analysis: Three commonly encountered firearms ( Glock17, Tokarev, and Colt) were fired at skin, wood, and cloth. AAS-analysis was performed with and without previous BTK3 application. The results clearly indicate that there is no significant interaction on the grounds of BTK3 use ( BTK3 vs . no- BTK3 [kit_nokit] [ Pb: p = 0.1309; Sb: p = 0.9111], material*kit_nokit [ Pb: p = 0.5960; Sb: p = 0.9930], distance*kit_nokit [ Pb: p = 0.4014; Sb: p = 0.9184], and firearm type*kit_nokit [ Pb: p = 0.9662; Sb: p = 0.9885]); hence, applying this field kit does not falsify later AAS outcomes. [ABSTRACT FROM AUTHOR]

Ballistic imaging systems can help solve crimes by comparing images of cartridge cases, which are recovered from a crime scene or test-fired from a gun, to a database of images obtained from past crime scenes. Many U.S. municipalities lack the resources to process all of their cartridge cases. Using data from Stockton, CA, we analyze two problems: how to allocate limited capacity to maximize the number of cartridge cases that generate at least one hit, and how to prioritize the cartridge cases that are processed to maximize the usefulness (i.e., obtained before the corresponding criminal case is closed) of hits. The number of hits can be significantly increased by prioritizing crime scene evidence over test-fires, and by ranking calibers by their hit probability and processing only the higher ranking calibers. We also estimate that last-come first-served increases the proportion of hits that are useful by only 0.05 relative to first-come first-served. [ABSTRACT FROM AUTHOR]

The defendant, the driver of the questioned car, allegedly extended his right arm over the passenger seat and fired a single shot from a 380 pistol out the passenger window with the pistol's breech within the car. A simulation of this shooting scenario using the same model car, but different year, was conducted to quantitate gunshot residue (GSR) contamination of interior surfaces within the car. The test car's dash and headliner/window frame above the pistol had the heaviest GSR contamination. The dash GSR from airborne deposition documents a firearm discharge within the vehicle. Transfer from GSR-contaminated hands or clothing to the dash is unlikely. The heavy GSR contamination of the headliner/window frame above the pistol likely documents the window from which the pistol was fired, but additional experiments are needed to verify. [ABSTRACT FROM AUTHOR]

Abrasion collar is usually described as a feature of bullet entry wounds caused by friction and indentation. The present case is that of the peculiar entry wound caused by a piece of flying shrapnel which was ejected from a furnace in a steel plant. The scrap metal which exploded in the plant was sourced from the West Asia region. The entry wound on the chest was circular and had an abrasion collar around it. The projectile was a cylindrical object of obscure origin. The forensic science laboratory put forth the possibility that the projectile was a component of an artillery fuze. A decades old study which employed high-speed photography has rejected the possibility that abrasion collars are produced by friction. High-velocity projectiles other than bullets can also produce abrasion collars as the rubbing of the bullet against the skin or its rotation are not the causative mechanisms. [ABSTRACT FROM AUTHOR]

Automated firearms identification ( AFI) systems contribute to shedding light on criminal events by comparison between different pieces of evidence on cartridge cases and bullets and by matching similar ones that were fired from the same firearm. Ballistic evidence can be rapidly analyzed and classified by means of an automatic image analysis and identification system. In addition, it can be used to narrow the range of possible matching evidence. In this study conducted on the cartridges ejected from the examined pistol, three imaging areas, namely the firing pin impression, capsule traces, and the intersection of these traces, were compared automatically using the image analysis and identification system through the correlation ranking method to determine the numeric values that indicate the significance of the similarities. These numerical features that signify the similarities and differences between pistol makes and models can be used in groupings to make a distinction between makes and models of pistols. [ABSTRACT FROM AUTHOR]

Based on the spatial relation between a primary and secondary bullet defect or on the shape and dimensions of the primary bullet defect, a bullet's trajectory prior to impact can be estimated for a shooting scene reconstruction. The accuracy and precision of the estimated trajectories will vary depending on variables such as, the applied method of reconstruction, the (true) angle of incidence, the properties of the target material and the properties of the bullet upon impact. This study focused on the accuracy and precision of estimated bullet trajectories when different variants of the probing method, ellipse method, and lead-in method are applied on bullet defects resulting from shots at various angles of incidence on drywall, MDF and sheet metal. The results show that in most situations the best performance (accuracy and precision) is seen when the probing method is applied. Only for the lowest angles of incidence the performance was better when either the ellipse or lead-in method was applied. The data provided in this paper can be used to select the appropriate method(s) for reconstruction and to correct for systematic errors (accuracy) and to provide a value of the precision, by means of a confidence interval of the specific measurement. [ABSTRACT FROM AUTHOR]

The consecutive matching striae (CMS) numeric criteria for firearm and toolmark identifications have been widely accepted by forensic examiners, although there have been questions concerning its observer subjectivity and limited statistical support. In this paper, based on signal processing and extraction, a model for the automatic and objective counting of CMS is proposed. The position and shape information of the striae on the bullet land is represented by a feature profile, which is used for determining the CMS number automatically. Rapid counting of CMS number provides a basis for ballistics correlations with large databases and further statistical and probability analysis. Experimental results in this report using bullets fired from ten consecutively manufactured barrels support this developed model. [ABSTRACT FROM AUTHOR]

This study investigates the legal status of modified shotguns in Turkey by examining the cases submitted to the Aydın Regional Criminal Laboratory between January 2006 and August 2008. A total of 351 shotguns used in crimes were examined. These guns were evaluated in respect of their type, size, caliber, fitness for use, and legal classification. Eleven percent of these shotguns had been modified and it was found that 55% of the modified shotguns were classified according to law 6136 and qualified as a pistol and 45% were classified according to law 2521 and qualified as nonstandard shotguns. Within the Turkish criminal justice system, a nonstandard shotgun attracts a less stringent sentence than a pistol. It would therefore appear that this sentencing structure is considered when modifying shotguns in Turkey. This is clearly a loop-hole in the legislation that could perhaps be investigated and closed. [ABSTRACT FROM AUTHOR]