This plot uses the real life murders of the Scarboro (people like myself who lived there use this short form of Scarborough) Rapist during the late 1980's as the plot. Paul Bernardo was a serial rapist and his wife Karla Homolka was jealous of the attention her husband was giving her younger sister, Tammy. Tammy died after Bernardo raped her while Karla helped. Bernardo turned from rape to murder in the 1990's. This is the exact same scenario used here.
Elaine Beretta was murdered on April 11, 1998.
Jennifer Gerrick was murdered on April 18, 1998.
This episode takes place in April 1998.