Kallie's mother's lowlife boyfriend is not the killer of Seward's wife. He killed Bullet, confessed to the murder of the 17 young women, and their rings were in his possession. Seward's son picked out his photo, but Kallie's mother negated that with the bad news that the murderous creep was in Alaska at the time Seward's wife was killed. Linden realizes that the boy was just trying to save his father - he'd seen Kallie's boyfriend's face in the news.
So with the pastor and now the pornographer taken out of the running, we're left with what I was talking about last week: Becker the unbalanced prison guard as the killer of Seward's wife.
But at least two questions need to be cleared up before we can definitely say it's Becker.
First, how did he come to know Seward's wife, or be at her home on the night she was murdered? We've seen Becker come to know Seward, of course, as Seward spends his time on time on death row. But Seward's there for the murder of his wife, which means Becker had to know Seward before that, and be motivated enough to kill Seward's wife. Anything less would be too much of a coincidence. Maybe my recollection is fuzzy, but I don't recall any history between Becker and Seward before Seward got to death row.
Second, how did Seward's boy come to draw the pictures of the place where the 17 bodies were found? If Callie's boyfriend, who presumably killed the 17, was in Alaska when Seward's mother was killed, and therefore had no connection to her killing, why would the boy know anything about the 17?
With The Killing, the plot is so intricate and intense that it's always possible to miss a piece of evidence or logic. On the other hand, inexplicable components would well mean that a theory is wrong. I'm looking forward to more.
See also The Killing 3.1-2: Poe Poetic Po-po ... The Killing 3.3: Hitchcockian Scene and More ... The Killing 3.7: "Opiate of the Masses" ... Killing 3.8: The Kidnapping, and a Prediction
See also The Killing Season Two Premiere ... The Killing 2.2: Holder ... The Killing 2.11: Circling Back ... The Killing Season 2 Finale
And see also The Killing on AMC and The Killing 1.3: Early Suspects ... The Killing 1.5: Memorable Moments ... The Killing 1.6: The Teacher ... The Killing 1.8: The Teacher, Again ...The Killing 1.9: The Teacher as Victim, Again ... The Killing 1.10: Running Out of Suspects ... The Killing 1.11: Rosie's Missing - from the Story ... The Killing 1.12: Is Orpheus the Killer? ... The Killing 1.13: Stretching Television