What does surveillance primarily aim to observe?

Surveillance primarily aims to observe persons, places, and things because it encompasses a systematic and often covert observation process to gather information regarding activities or behaviors of specific subjects or locations. This method is vital in criminal investigations, as it helps law enforcement identify potential unlawful behaviors, gather evidence, and ultimately build a case without the immediate knowledge of those under observation.

In the context of criminal investigations, understanding what is being monitored is crucial. Surveillance can include watching specific individuals suspected of criminal activity, monitoring locations prone to illegal activities, and observing objects that might be relevant to ongoing investigations.

The other options focus on specific aspects of law enforcement operations but do not encompass the broader scope that surveillance represents. Judicial proceedings involve the judicial system and legal processes, while traffic violations and illegal immigration are specific areas of law enforcement that may sometimes utilize surveillance but do not define its primary purpose.