Near the end of Winter's Bone, it is revealed that Jessup Dolly (Ree's father) was murdered because he was trying to collaborate with the sheriff and turn in other meth cookers to escape a long prison sentence.
Teardrop implies that the sheriff himself leaked the fact of Jessup's collaboration and got him murdered. It is also implied the sheriff knew from the beginning that Jessup was murdered, and that the sheriff himself had secretive dealings with the meth cookers in his community, specifically the Thump clan who are apparently responsible for Jessup's death. Finally, there's a strong implication that the sheriff seeks to kill Teardrop for knowing all this, and their final encounter at the end nearly culminates in a shootout, but the sheriff backs off since it will be harder to explain the shooting with Ree in the passenger seat and possibly a second victim.
All of this is implied. I'm wondering if there's any additional evidence for this anywhere, or, conversely, any evidence against this theory?
I'm not an expert on Film Noir, but it seems like a feature of the genre to leave some or most details of the mystery mired in ambiguity and never fully resolved. However, it seems that by watching carefully, a complete picture of what happened does emerge: Jessup tried to cut a deal with the sheriff by testifying against the Thump clan to escape his looming long prison sentence, the sheriff was too deeply in cahoots with the Thumps so he betrays Jessup to the Thumps who murder him, then the sheriff plans to get rid of Teardrop because he is aware of this, and the horror of the situation is the complete futility and lack of any hope for justice, even specifically from the main public figure who should uphold it.