What is the point of 一名 in this sentence?


(Taken from ジョジョ６部)

> 「女性受刑者が一名頭部を砕かれ変死をとげたというのに…」

I don't really get the point behind 「 **一名** 」in this sentence.

My guess is that the sentence (badly) translates to something like: "And
although one/a female prisoner got her skull broken and died an unnatural
death..."

So what does 「 **一名** 」add to the meaning? Is it used as "count-word", in
order to specifically point out that it was **one** prisoner or is there
something wrong with my interpretation of the sentence? Or is it in the end a
grammatical necessity?

(To give some context: The sentence (in my opinion) literally states what
happened. Due to an incident one prisoner was brutally murdered before above-
stated sentence was uttered)

