beyond a shadow of a doubt vs beyond a doubt

beyond a shadow of a doubt and beyond a doubt both are adverbs.

Word	Noun	Adjective	Verb	Adverb
beyond a shadow of a doubt	No	No	No	Yes
beyond a doubt	No	No	No	Yes

As adverbs, beyond a shadow of a doubt and beyond a doubt are synonyms defined as:

beyond a shadow of a doubt and beyond a doubt: in a manner or to a degree that could not be doubted

Other synonyms of beyond a shadow of a doubt include beyond doubt, indubitably.

beyond a shadow of a doubt (adverb)	beyond a doubt (adverb)
in a manner or to a degree that could not be doubted	in a manner or to a degree that could not be doubted