I was left with a different feeling than after most Cold Case episodes as I did not find it as sad as the others. In fact, I though it was rather enjoyable in that the team's work saved lives given that the killer said he had much work to do when he got out.
I also enjoyed the change to the standard plot line in that the team was not looking to find a killer, but to tie a murder to a specific individual.
I do not want to imply for a moment that Roy is not responsible for his actions because he is, as I believe we all are. At the same time, I thought it was an excellent portrayal of how deeply one's character can be molded by authority figures. The utterly contemptible reaction of his father to Roy's innocent feelings for a girl and the aunt's bizarre over-reaction to innocent fun with Kelly at The Rocky Horror Picture Show sowed the seeds for what the young man became.
Obviously Roy had his own serious psychological problems because sadly many, many children are abused and do not become criminals never mind serial killers. Still, as Aunt Louise horrifying recognizes, she played a part, however small, in how Roy turned out.