The performance of BALİSTİKA 2010 system for 9 mm × 19 mm and 7.65 mm × 17 mm cartridge case correlation

Investigation of the variability in the tool marks produced by modified blank firing pistols on fired 7.65 mm projectiles

Firearms identification has an important place in forensic ballistic investigations since the weapons are widely used in criminal offences. Firearm examiners resolve many case files, through the use of automatic systems or comparison microscopes. Advanced forensic technologies like BALİSTİKA helps to record and analyze non standard ballistic evidence. In today's world, with the ease of access to materials and production technique information, pistols modified from blank firers are frequently encountered as crime tools. In this study, the characteristics of 7.65 mm fired cartridge cases obtained by controlled shots from blank firing modified pistols were examined, and their detection performances were compared by means of the Balistika system. Although distinctive differences are not expected after successive test shootings, balistically important changes were seen after the use of blank firing modified pistols and the 3D imaging system proved to be useful in observing such differences. The analyses showed that the modifications in weapons lead to variation in the ballistic characteristics and reduce the accuracy of the detection performance, which may result in flawed forensic decisions. It was also found that the deviations in ballistic impressions of modified blank firing pistols were greater than that of standard fabricated and hand-made pistols. This unique study contributed to the forensic sciences literature by focusing on the impact of modified weapons on ballistic characteristics.

Classification of fired cartridge cases using 3D image capture and a comparison of database correlation method performance

When firearms are used, they leave unique marks on the fired bullets and shells. Examining these marks gives clues about the crime scene and the weapon of the crime. However, due to the increase in the number of incidents in which firearms are used, the increase in the amount of evidence makes ballistic investigations very difficult and prolongs the analysis time of the evidence. With the automatic image analysis and identification system, ballistic evidence can be examined very quickly and used to classify possible matching evidences. In this study, we present an approach based on Image Similarity Measurement for forensic examination of cartridges from automatic pistols. For this purpose, we used 500 images of 9 × 19 mm and 500 images of 7.65 × 17 mm cartridge cases obtained from 20 different brands and models of pistols. We divided the images of bullet cartridges into four different categories as breech face, firing pin, ejector mark, and combined evaluation, and we obtained these images from the BALİSTİKA 2010 system. We investigated the classification and matching performance of the obtained four category images using 4 different methods: Structural Similarity (SSIM), Root Mean Square Error (RMSE), Peak Signal to Noise Ratio (PSNR), and Universal Image Quality Index (UQI). The results show that our Structural Similarity (SSIM) approach is effective in classifying and matching ballistic evidence.

Investigation of Ballistic Evidence through an Automatic Image Analysis and Identification System

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.