dead person vs deceased person

dead person and deceased person both are nouns.

Word	Noun	Adjective	Verb	Adverb
dead person	Yes	No	No	No
deceased person	Yes	No	No	No

As nouns, dead person and deceased person are synonyms defined as:

Other synonyms of dead person include dead soul, deceased, decedent, departed.

dead person (noun)	deceased person (noun)
someone who is no longer alive	someone who is no longer alive