When do they clear Donnie of his wife's murder?

When do they clear Donnie of his wife's murder?The took the coffee cup from the trash for d.n.a. testing,but there's been no mention of it.

And according to my sources there are only two episodes left in this season.


So will it happen during the next two episodes,or do I have to wait until next season?

I should have known those alien maggots booby trapped this sub.