mccready: it was shocking. everybody was just devastated. i just kept thinking, why did he have to kill her? reporter: police are not discounting the possibility that the cases may be connected. mccrary: there were similarities. both had been physically assaulted. both had been asphyxiated. both had bruising to their bodies as though someone had been kneeling on their back, maybe using a ligature strangulation or strangling them from behind. paul hunter: we have to find who did this, or more young girls are gonna die. this danger is out there. the scarborough rapes began in may of 1987, but it would be six years before the police would get their first big break in this case. the lab that analyzed dna didn t have a lot of resources, so samples sat for a number of years.
once homolka came forward, things started lining up. rosen: she tells them about the two young girls who were being sexually molested kristen and leslie. and she told them, what s more, we videotaped all of it. karla and bernardo they taped everything. homolka: here is my husband. you d see them on vacation, and they taped the sexual abuse and assault of these young women. mccrary: one of the things that our research has shown is these sexually violent offenders memorialize their crimes. so, we were able to get a search warrant to look for those tapes. bevan: we have obtained a search warrant. we entered the premises last evening and began our work. paul hunter: and they looked for 71 days inside that pretty, little house in st. catharines. they couldn t find it. reporter: police tore the house apart,
- [announcer] do you have an invention idea but don t know what to do next? call invent help today. they can help you get started with your idea. call now 800-710-0020. reporter: 28-year-old paul bernardo is in protective custody at the metro east detention center. brad hunter: paul bernardo is already known as the scarborough rapist, and now he is busted being part of these horrific rapes and murders of these young girls, leslie mahaffy and kristen french. reporter: there s a lot police aren t saying about this investigation. what breakthrough led to the arrest? is bernardo s wife being questioned? rosen: karla homolka was speaking with the police. mccrary: when this thing came crashing down, she rolled. she turned on paul. paul bernardo has been charged with two counts of first-degree murder of leslie mahaffy
in the history of canada. it started with the scarborough rapes. reporter: since may 4, 1987, numerous sexual assaults have been attributed to a man dubbed the scarborough rapist. paul hunter: his m.o. was to go up behind his victims and grab them from behind to make sure they couldn t see him. pron: he had put a knife to their throat and said, if you look at me, i ll slit your throat. kenzora: and the attacks, each one got a little bit more violent as time progressed. mccrary: our fear was if he wasn t stopped soon that this is gonna escalate to murder. kenzora: no one had really seen the attacker s face, so the police didn t really have much to go on, but then the attacker made a mistake. pron: on his 13th victim, a lady was walking down the street and he was walking towards her. she was able to see his face. and she was able to give police a very detailed description,
mccrary: the one thing that she forgot to mention when she was talking to the police, raping and killing her own sister. the death of tammy homolka had been considered accidental at the time, but they were responsible. shlosberg: paul had an unhealthy infatuation with karla s younger sister, tammy homolka. tammy was a virgin, and that was very appealing to paul, who often criticized karla for not being pure. he is, according to karla homolka, harassing her to have sex with her little sister. he keeps pressuring her and pressuring her, and eventually she agrees. karla and paul come up with this plan