How long before guards forget that you murdered someone?

So, In my most recent playthrough I’ve been running around the map slaughtering pretty much anyone that isn’t a potential questgiver or shop owner. I made the mistake of killing too many of these people on my last playthrough, and found that some side quests are inaccessible. And of course, less shops to buy from, if I wasnt thieving.

But anyway, mostly I dont become wanted, because I’m careful to not kill in plain sight of view of others. But sometimes it catches up. Now theoretically, being wanted for murder should never, ever go away,you should still be wanted no matter how long you wait. But I’m just wandering if anyone has done any tests? Do bounties for murder eventually go away?

I don’t think they do…