New projectiles specialized for creating and recovering trace evidence at a crime scene are provided. A wide variety of embodiments are provided, covering several use scenarios—including, but not limited to, home security devices, which may be built into an entryway or other building structure, and law enforcement guns. In some embodiments, a projectile within a projectile is provided, which fires in the direction of a primary impact. A sampler device is provided within some projectiles, which may comprise tracing barbs, containers for analytes and even a hypodermic extraction apparatus. In some embodiments, projectiles have rebounding devices, which may overlap with aspects of the sampler device, for developing distance from a criminal suspect. Other aspects, such as GPS, fasteners and defense mechanisms, are also disclosed, which encourage recovery by the authorized user and deter interception.