Bullets were fired at an elementary school. The projectiles penetrated the exterior walls and were acquired from within the building. The focus of the investigation was to determine the type of rounds used, make of the projectile(s) and match it to reference ammunition from a local rifle range.
The analysis was performed by various microscopy techniques that enabled measurements of the rounds and characterization of the projectiles and their coatings. Law enforcement utilizes this information in their efforts to trace the ammunition to a suspect. The spent rounds were found to be consistent with .177 air rifle pellets and .22 caliber rounds. Further investigation matched the .22 caliber rounds to those found at a local rifle range.