detection vs police work

detection and police work both are nouns.

Word	Noun	Adjective	Verb	Adverb
detection	Yes	No	No	No
police work	Yes	No	No	No

As nouns, police work is a hypernym of detection; that is, police work is a word with a broader meaning than detection:

Other hypernyms of detection include police investigation.

detection (noun)	police work (noun)
the act of detecting something; catching sight of something	the investigation of criminal activities
a police investigation to determine the perpetrator
the perception that something has occurred or some state exists
the detection that a signal is being received