The plot discovered
When Larissa and Tyler Schuster flew out of town on a planned family vacation to visit Disneyworld and Larissa's family in Missouri, Clovis Police turned their attention to James Fagone. They called Fagone in for a series of interviews, little by little getting more and more of the story. In his third police interview, Fagone admitted to helping Larissa Schuster murder her former husband.
In an attempt to corroborate Fagone's story, they asked him what happened to the stun gun he had used to incapacitate Tim Schuster. Fagone told them that he had disposed of it in a Porta-Potty at a nearby construction site. Sgt. Jim Koch and Det. Vince Weibert drew the unpleasant assignment of digging through human waste to find the stun gun. When they retrieved it, they concluded Fagone was telling the truth about what happened.
The most repugnant bit of evidence-collecting, though, was yet to come.