Yes ,it does.
"prosecution of anyone who PLAYED a role in the girls disapearance and death"
So she seems to have no doubt someone did play a part in that ,in the first part so it does lend itself to wonder what she means because she has already said what happened to her ( missing and murdered) and that she is hoping toxs reports will help her prosecute sucessfully.
Now Played is an interesting word IMO.
Respectfully, I would not read a whole lot into any one statement, let alone dissecting individual sentences and sifting individual words for added meaning.
I wonder if the tox screen are being bought up because of something like someone was on a known prescription and they have a good idea that person gave someone else some of the prescription And that person who was given a part is a suspect ?
Certainly possible. It is also, I believe, routine. That said, let's explore this idea further.
Let's say, for example, that the toxicology results come back and Celina is found to have a high dose of drug XYZ in her system, and further that drug XYZ is a medication perscribed to someone in her household. This would be a significant discovery! It would tell us exactly who--
--Wait. Sorry. Actually this fact, in itself, answers nothing. But it could be a step towards an answer. For example, if the concentration were extreme and beyond lethal it might suggest (note the word might in there) that Celina was not quite as happy as she has been described. Alternatively, what if this medication was found in a high but less than lethal dose and it was known as a recreational drug -- that too might suggest some answers, like perhaps an accident. Or what if she is found with something like a date-rape drug in her system?
Note that none of these results, alone, nail this thing shut or necessarily point at anyone. However, when combined with whatever other information the police have it might complete the puzzle.