Mark Liberman of Language Log touches on the question of redundancy in legal language.
One focus of redundancy is coupled synonyms, to quote Mellinkoff’s term:
bq. A long habit of coupling synonyms persists in American legal usage, e.g. authorize and empower, null and void, true and correct. The habit is compounded of antiquated literary style, the mixture of languages we now call English, the lawyer’s gamble on venial repetition against mortal omission, and a misplaced reliance on the precision of what has endured.
(Mellinkoff’s Dictionary of American Legal Usage – see this comparison of law dictionaries)
Mellinkoff has a long list, as does Garner’s Dictionary of Modern Legal Usage, under Doublets, Triplets, and Synonym-Strings. Garner mentions the theory that a Latin word was paired with an Anglo-Saxon one for wider comprehension (acknowledge and confess, act and deed, goods and chattels); the rhetorical elements; and the element of ignorance, where the writer doesn’t know the exact definition of any of the terms and so throws them all in. Some of these doublets/couplets are terms of art and most are purely redundant, but even in the latter case, an inventive court may surprise the lawyers by construing shades of meaning, especially if the doublet is a rare one.