The prime suspect is Omar Dixon. Stack helps catch the guy before he skips the country. He lets Beckett do the honors of interviewing him. Stack is impressed with how she works. Castle notices this guy eyeing his partner. As for Dixon, he’s not the killer. There’s only one other person who could get close enough to Dale Tanner—his son, Sean. The kid was ticked because his dad put his crusade ahead of his family. He was pushed over the edge when he found out about his affair. Sean wanted to make his dad pay for what he’d done. Case closed.
Stack asks to have a private chat with Beckett. He wants to know what she has in mind for her future. Stack used to be a homicide detective, too. He sees bigger things for her. There’s a job opening in DC with the Attorney General where she’d get to work on the most challenging cases out there. The stakes are high and the outcomes can affect history. Stack hands over a number to call to schedule an interview. Beckett promises that she’ll think about it. However, she makes no mention of this intriguing job offer to Castle.