forensics vs police work

forensics and police work both are nouns.

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

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

forensics: scientific tests or techniques used in the investigation of crimes
police work: the investigation of criminal activities

Other hypernyms of forensics include police investigation.

forensics (noun)	police work (noun)
scientific tests or techniques used in the investigation of crimes	the investigation of criminal activities