What must an investigator do if a subject is not apprehended after a warrant is obtained?

An investigator must prepare a wanted folder if a subject is not apprehended after a warrant is obtained. This action is essential because the wanted folder serves as a critical centralized resource that contains all pertinent information about the subject, including physical descriptions, known associates, criminal history, and details about the warrant itself.

By compiling this information, the investigator ensures that data is readily available to law enforcement agencies and others involved in the apprehension effort. The wanted folder can be distributed to patrol officers, made available on law enforcement databases, and used in public awareness campaigns if necessary, thereby increasing the chances of locating and apprehending the subject.

The other choices, while they may have their own merit in different contexts, do not focus on the immediate steps needed for apprehension. Filing a civil complaint would be unrelated to the criminal apprehension process. Contacting the subject's last known employer or notifying family members might sometimes provide leads, but they are not standard procedures for managing a warrant situation and do not aim directly at apprehending the subject.