Sharp Objects Ending Explained

6. Who Killed Who?

Although the final few minutes revealed that it was Amma, not Adora, who murdered Ann and Natalie, the first end-credits sequence made it clear she wasn't working alone. With the help of her two roller-buddies, the three girls killed and tortured the children in Wind Gap, however Amma killed her new friend Mae single-handedly in St. Louis.

Though it comes as a surprise that Amma had help, the show constantly informed viewers that the murders couldn't have been carried out alone, even implicating the three girls directly.

They're seen at the window crime scene immediately before the body shows up (and are shown across the street when it's discovered, marvelling at their own work), while they're also depicted early on disrespecting Ann's memorial by carelessly throwing around the toys placed for her.

Why the two friends helped kill two people isn't totally explained, but there are hints throughout that make it clear the killer has a hold over them. Amma already mentioned that she could get both boys and girls to do whatever she wanted, and it seems as though that extended to murder.