Looking for an investigative true crime podcast, one case per season !

So I m true crime podcast addicted but I really don’t enjoy one case per episode podcasts , as I m looking for something deeper , something that really makes a difference, finds new leads etc . I m listening to podcasts every day while walking dogs so I m running through a lot of them and right now I feel like I listened to all the good ones already .

I really enjoyed: to live and die in LA, someone knows something, your own backyard , unraveled, hide and seek , culpable etc .

Looking for recommendations, preferably missing / murder cases .

Thanks a lot in advance :)