Well, legal English developed in an amalgamation of English and Norman French and Latin.
English being what most of the plaintiffs and defendants actually spoke, Norman French being the language of the people making the laws and Latin being the showing off language for general ponciness and appeal to authority (Roman law and jurisprudence - which contrary to what idiots like Farage et al would have us believe has always played a large part of English jurisprudence).
So yes, you have a lot of stuff which is “English root” and “French root” or “English root” and “Latin root”. The Wikipedia article has some examples, there are plenty more.
The theory is that both were used to make sure the meaning got across whichever language the person reading/hearing it was more comfortable in.
Plus it also has the rhetorical effect @euansmith pointed out and advocates are all giant hams.
Nowadays of course they all have the weight of tradition and if you want to get a bunch of lawyers really het up, try suggesting that they shouldn’t use them anymore. 
