Someone on another site pointed out that the lady sitting next to Kirsten in Harry's photos looks like the actress who played his wife in episode 20. There is a teenage girl sitting next to her. Walker was supposed to have a 16 year old daughter.
If that's the case, then Walker is probably dead. And if that's the case, I'm not happy about this.
EDIT: Yep, that's the actress who played Walker's wife. Her name is Tracie Thoms. You can see her name tag in a photo Joe posted:
Here is the IMDB page for Unforgettable with Tracie listed as Walker's wife
http://www.imdb.com/title/tt6527272/?ref_=ttep_ep20