Technical note: A silenced hybrid 3D-printed self-loading pistol of the YEET family

Since the release of the first 3D-printed firearm, "The Liberator," the occurrence of 3D-printed firearms in criminal activities has increased, highlighting the need for forensic research on these weapons. This study presents a technical examination of a 3D-printed firearm received by the National Institute of Criminalistics and Criminology (NICC), focusing on its design, ballistic performance, and its potential for microscopic comparative analysis. The firearm, resembling a 3D-printed pistol Yeet22, is primarily constructed from polymer parts, with the exception of the firing pin, barrel, and various springs and screws. Notably, this firearm includes a previously undescribed sound suppressor. Velocity tests revealed that the bullet velocity was lower than that of a standard .22 LR firearm, yet still high enough to be lethal at its maximum speed. Forensic examination of the fired cartridge cases showed distinguishable chamber marks, facilitating comparative analysis. Comparisons of the striation marks on the reference bullets was also possible although only for bullets fired in close sequence to each other. However, the reliability of this 3D-printed firearm was found to be significantly lower than conventional firearms. These observations underline the challenges and importance of forensic investigations of 3D-printed firearms, as they become more prevalent in criminal contexts.