Not right now from what I can think of.
But, adding "solved mystery"-filters is on the todo-list for our "live map" which is a work in progress. We are planning to make a real release of it in the weekend, and this far we have only mentioned it on Facebook and Twitter, to sneak it out there while testing.
The map was added to the menus just a few minutes ago, but here is the link: http://project-gc.com/LiveMap/
I can not promise exactly how our filters regarding solved mysteries will work. The most common use case is probably to only include solved ones, but I see your point and we will try to keep it in mind (I noted it down in the livemap-document).