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•A sample set of cartridge cases was collected from various people firing the same gun and ammunition.•A proposed method used the statistical data from the sample set to estimate a shooter’s position from ejected cartridge cases.•It was found that with an increasing number of cartridge cases used for shooter position estimation, the errors and standard deviation decreased, improving estimation results. Ejected cartridge cases in shooting incidents are useful in crime scene reconstruction to approximate the location of a shooter and the dynamics of an encounter. The purpose of this study is to propose a method to approximate a shooter’s position based on a reference sample set of cartridge case ejection patterns. This research is significant as there are no blind studies that determine the precision or errors when estimating a shooter’s position based on cartridge case ejection patterns. Understanding the errors associated with shooter position estimation may give investigators a standardized method for establishing a reference set of cartridge cases which reflect the behavior of ejection patterns under controlled variables, while having a more reliable method when estimating a shooter’s position. A reference sample set of more than 312 cartridge cases was collected from various people firing the same gun and ammunition from a known position and at different heights using a double-handed grip. The proposed method used the statistical data from the reference sample set and was tested on blind data sets to determine the errors and precision using “unknown” shooters. The blind testing sets ranged between 1 and 6 ejected cartridge cases with a known direction of fire. It was found that with an increasing number of cartridge cases used for shooter position estimation, the errors and standard deviation decreased, improving estimation results. With a blind set of 6 cartridge cases, the errors were shown to average 122 cm from the known firing position. The applicability of this method depends significantly on the type of firearm, ammunition, human factors, environment and other factors.

Unmanned aerial vehicles (UAV) are growing in popularity, and recent technological advances are fostering the development of new applications for these devices. This paper discusses the use of aerial drones as a platform for deploying a gunshot surveillance system based on an array of microphones. Notwithstanding the difficulties associated with the inherent additive noise from the rotating propellers, this application brings an important advantage: the possibility of estimating the shooter position solely based on the muzzle blast sound, with the support of a digital map of the terrain. This work focuses on direction-of-arrival (DoA) estimation methods applied to audio signals obtained from a microphone array aboard a flying drone. We investigate preprocessing and different DoA estimation techniques in order to obtain the setup that performs better for the application at hand. We use a combination of simulated and actual gunshot signals recorded using a microphone array mounted on a UAV. One of the key insights resulting from the field recordings is the importance of drone positioning, whereby all gunshots recorded in a region outside a cone open from the gun muzzle presented a hit rate close to 96%. Based on experimental results, we claim that reliable bearing estimates can be achieved using a microphone array mounted on a drone.

A wealth of research in recent decades has seen the economic approach to human behavior extended over many areas previously considered to belong to sociology, political science, law, and other fields. Research has also shown that economics can provide insight into many aspects of sports, including soccer.Beautiful Game Theoryis the first book that uses soccer to test economic theories and document novel human behavior. In this brilliant and entertaining book, Ignacio Palacios-Huerta illuminates economics through the world's most popular sport. He offers unique and often startling insights into game theory and microeconomics, covering topics such as mixed strategies, discrimination, incentives, and human preferences. He also looks at finance, experimental economics, behavioral economics, and neuroeconomics. Soccer provides rich data sets and environments that shed light on universal economic principles in interesting and useful ways. Essential reading for students, researchers, and sports enthusiasts,Beautiful Game Theory is the first book to showwhat soccer can do for economics.