Randi Mebruer

Randi Jane Mebruer, 28, a White woman, vanished from her home in Zachary, Louisiana, on the evening of April 18, 1998, after a simple errand to a nearby video store and a quiet return home with her young son. By morning, the child wandered to a neighbor and said his mother was missing, and adults who stepped inside the house found what no one wanted to imagine: blood on the floor and the first signs that this wasn’t a disappearance someone could explain away as a walkout.

Investigators ...