Today, I definitely think I enjoyed the back-story for Rossi much more than I enjoyed the case, even thought the case was a good one. A killer cleansing the city of homeless people is - admittedly, the not very unique storyline - but nonetheless, a very enjoyable and interesting case as well.
There was an absolutely hilarious moment when Reid was like - "She was in the city for 2 months and didn't make any friends. I thought that only happened to me!" - or something along those lines, and I thought that comment was really funny and I was laughing!
The back story was phenomenal and very insightful - and I think the 'dedictaion' for the next book was perfectly incorporated into this episode. Would love to read that book!
Keep it up, Criminal Minds! Am definitely looking forward to the next one!