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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]

The use of carbon nanotubes in composite hard armor is discussed in this study. The processing techniques to make various armor composite panels consisting of Kevlar®29 woven fabric in an epoxy matrix and the subsequent V50 test results for both 44 caliber soft-point rounds and 30 caliber FSP (fragment simulated projectile) threats are presented. A 6.5% improvement in the V50 test results was found for a combination of 1.65 wt% loading of carbon nanotubes and 1.65 wt% loading of milled fibers. The failure mechanism of carbon nanotubes during the ballistic event is discussed through scanning electron microscope images of the panels after the failure. Raman Spectroscopy was also utilized to evaluate the residual strain in the Kevlar®29 fibers post shoot. The Raman Spectroscopy shows a Raman shift of 25 cm−1for the Kevlar®29 fiber utilized in the composite panel that had an enhancement in the V50 performance by using milled fiber and multi-walled carbon nanotubes. Evaluating both scenarios where an improvement was made and other panels without any improvement allows for understanding of how loading levels and synergistic effects between carbon nanotubes and milled fibers can further enhance ballistic performance. [ABSTRACT FROM AUTHOR]

The article describes a property of ellipses which was observed by the physicist Jean-Marc Richard in connection with a problem from ballistics. The maximal perimeter of a parallelogram inscribed in a given ellipse can be realized by a parallelogram with one vertex at any prescribed point of the ellipse. The well-known geometric object to which the foregoing discussion relates is the orthoptic circle of Monge, who proved that the locus of points from which one sees an ellipse at right angles is a circle.

Focuses on the role of mathematician and United States Army officer Oswald Veblen in bringing mathematics into the First World War. How academic mathematicians reacted to army life; Overview of the mathematical ballistics of 1918; Details on the application of mathematical ballistics in the army.

Discusses ballistics and ballistic trajectory, the use of geometry on parabola and its application on the science of motion. Overview of the Galilean model; Details on the resisted shot; Information on enveloping parabolas; Details on the mechanics.