Kevin Works in a Police Department and Specializes in Homicide

Kevin works in a police department and specializes in homicide cases. He has detailed knowledge on firearms. In his last homicide case, Kevin found a bullet at the crime scene and knew that the bullet was fired from a gun that is no longer manufactured. He immediately got his technicians to create a 3D image of the bullet and looked it up in a national firearms database to identify the gun and its last owner. This scenario illustrates that Kevin is:

A) participating in a sting operation.
B) working as a forensic psychologist.
C) extracting trace evidence.
D) using ballistics technology.