something else about robert denney.lived in the same complex as corey parker. with a direct line of sight into her apartment. >> robert denney told some co-worker about this woman that lived in an apartment below him. and he began to talk about how he would watch her. and even went so far to graphically describe he would masturbate while watching her. >> when police decided to question denney again, his sister told police that he had left the area. >> she had actually kicked him out of the home she shared with her husband because of his odd behavior. staying up all hours of the night his addiction to photography, he told one law enforcement officer that she had awoken to him standing over her bed and staring at her. >> then police discovered another thing. robert denney's brother was serving life in prison for stabbing a woman 101 times. >> what are the chances of two young men coming out of prison committing the same murders. and was he trying to emulate his brother? ♪ and there's nothing really good around ♪ ♪ turn ar