: Dr. Reid discovers that the two unsubs communicate through an encrypted blog using song lyrics as a code. The BAU identifies Harris's partner as his next-door neighbor, Steven Baleman .
: The episode begins with the arrest of William Harris , a successful lawyer and family man who matches the profile of a serial killer responsible for the disappearances of several young women. Harris remains calm and arrogant, confident he will be released because the police lack physical evidence. [S4E12] Soul Mates
: The pair alternated their victims between white and black women, a detail that initially confused local law enforcement but helped the BAU refine the profile of a duo. [S4E12] Soul Mates