Defense Atty will rip this apart- sheath could have been in a piece of clothing for years before it came out in the dryer, likewise the sheath could have been in the dryer for years before LE discovered it. It could be from/for something else for someone else that BM wasn't aware of- daughters, wife etc.. They can't link it to the drug and they can't link it to the time and they can't link it to the person (BM). I am 100% convinced it is linked to all those things, but there isn't any evidence that it is and a good atty will make sure everybody knows that.
100% this. They've found a dart cap/sheath (on the second search of the house, iirc) that may or may not be linked to the crime.
Some posts above are speculating that it won't be important, but that opinion seems at odds with the statements of the prosecutor at the close of the prelim.
I think it's clear they believe it's important to their theory of the case, and jmo but I see some big issues with it.