Elva's mother, Mary Jane Heaster, hadn't liked Edward, and despite a lack of evidence, she was convinced he had murdered Elva. But given that both "investigating crimes properly" and "taking women seriously" hadn't yet been invented in 1897, Mary Jane could do nothing but pray that somehow the truth would come to light. Then, for four nights in a row, Elva herself supposedly appeared in Mary Jane's dreams, explaining that her husband had crushed her neck because he hadn't liked his dinner. To prove that her spinal cord had been severed, Elva's ghost turned her head around 180 degrees, then walked away while staring at Mary Jane. A creepy thing to do to your mother, but at this point it seems clear that Elva wasn't fucking around.
Mary Jane took this revelation to the local law guy, John Preston, and we'll never know whether Preston believed her or simply wanted to get the crazy-sounding woman off his back, but her panicked ramblings convinced him to look into the case. After learning about Edward's strange behavior, Preston, the only competent non-dead person in this story, ordered the body to be exhumed. It took him about five seconds to conclude that, indeed, Edward killed Elva.
However, the strangest part of the story isn't the claims of Elva haunting her mother or twisting her neck like an owl to light a fire under her ass -- it's that all this ghostly nonsense held up in court. During Edward's trial, Mary Jane was allowed to testify, and while it was Shue's lawyer's intention to make her look like a crazy old lady, this backfired horribly when Mary Jane stood her ground and managed to convince the jury of what she had experienced. The trial's acceptance of this ghostly evidence has led some to call it "the only known case in which testimony from [a] ghost helped convict a murderer," which is emblazoned on a plaque celebrating Elva Shue, who got her killer from beyond the grave.
via Mental Floss