police blotter vs day book

police blotter and day book both are nouns.

Word	Noun	Adjective	Verb	Adverb
police blotter	Yes	No	No	No
day book	Yes	No	No	No

As nouns, police blotter and day book are synonyms defined as:

police blotter and day book: the daily written record of events (as arrests) in a police station

Other synonyms of police blotter include blotter, charge sheet, rap sheet.

police blotter (noun)	day book (noun)
the daily written record of events (as arrests) in a police station	the daily written record of events (as arrests) in a police station