When I first saw this episode back in the day I didn't like it and the intervening years have done nothing to change my mind.
The main characters and their motivations are simply too unbelievable. For me, their relationship lacked any aspect that would have made it credible. Their crime was simply too over the top to make sense - why kill the parents rather than just kidnap the child? This is the second episode in a row that is trying to examine the idea that domestic violence creates a cycle of violence that carries itself forward into new generations. It's the second episode in a row in which it didn't work.
Visually this episode returns to the visual style of the first season - dark, sleek, stylish. On the evidence front, there is a major problem - you can't get a fingerprint from a person's eye, a point that was so glaring I couldn't past it.
The nadir of the season thus far.