I'm in need of a complex sentence that lists out three requirements, and the facts that satisfy those requirements. Here's an example of what I'm referring to, using the "motivation, means, and opportunity" elements of a murder:
The prosecution had all the evidence they needed for a murder conviction. Alfonso had the motivation to see his friend dead—full control of the company—,the means to kill him—a whole lab with poisonous chemicals—, and the opportunity to do so—the dinner party.
Is this a proper emdash and comma usage? I could use a semicolon instead, like so:
The prosecution had all the evidence they needed for a murder conviction. Alfonso had the motivation to see his friend dead—full control of the company; the means to kill him—a whole lab with poisonous chemicals; and the opportunity to do so—the dinner party.
But then the three requirements get mixed up with facts, visually, making the list harder to parse. A final option would be using parenthesis:
The prosecution had all the evidence they needed for a murder conviction. Alfonso had the motivation to see his friend dead (full control of the company), the means to kill him (a whole lab with poisonous chemicals), and the opportunity to do so (the dinner party).
But the use of parenthesis here seems out of place with the drama of the facts. Is it proper to use emdashes and commas as I did in the first example? What would be the best construction of the sentence?