Good interview with Sarsgaard and Sud. It actually reveals whether Seward killed his wife or not. Not sure if it's a spoiler of something we will learn in the season finale or if it is just a writing reveal. It does seem odd to me that there would be a definitive answer to that if they don't plan on revealing to the audience during the show.
http://www.buzzfeed.com/kateaurthur/the-killing-spoilers-peter-sarsgaard-veena-sud-interview
http://www.buzzfeed.com/kateaurthur/the-killing-spoilers-peter-sarsgaard-veena-sud-interview