Editor's note: This story was originally published in the fall of 2016 during Michael Peterson's retrial. A request for dismissal was rejected, and the case continued into 2017, when he eventually entered an Alford guilty plea. The owl theory never made it to court. The 15-year-old legal proceedings against author Michael Peterson for the alleged murder of his wife, Kathleen, constitute one of the more notorious and extensively documented criminal cases of our time. It has provided fodder for two Dateline segments, a Lifetime movie, an expansive documentary film series, and dozens of true-crime television episodes and podcasts. It is lurid, tinged with drugs and alcohol, replete with an ongoing extramarital affair with a prostitute, and soaked in blood—lots of blood. It also spawned a criminal defense theory that sounds like a punch line: The owl did it. But it’s not a joke. And even though the "Owl Theory," which states that a Barred Owl is responsible for the...