Warning: Extremely disturbing content ahead, continue at your own risk.
1. Serial killer Dennis Rader gave himself the nickname "BTK", standing for "bind, torture, kill" — how he killed his victims.
2. His series of murders took place over a long period of time from 1974 to 1991.
3. But he wasn't caught until three decades later.
4. In total, he killed 10 people.
5. He enjoyed dressing up as his victims and would take selfies of himself that way.
6. He used to cut out female figures from magazine ads and then draw ropes and gags on them.
8. He actually studied criminal justice in college.
9. Rader was active in his church, and he served as a Boy Scout leader.
10. His first murders were four family members, who he strangled to death.
11. Joseph and Julie's bodies were discovered by their three older children Charlie, Danny, and Carmen.
12. Semen would often be found at his crime scenes, but he never had sex with any of his victims.
13. Rader liked to collect "souvenirs" from his killings — often times underwear.
14. He described his preferred masturbation practice as "motel parties."
15. His last murder was committed in 1991.
16. One of Rader's victims actually survived an attack.
17. Some time after his second killing, he wrote a letter detailing the murders of the Otero family and said: “The code words for me will be…bind them, torture them, kill them, B.T.K.”
18. He also wrote a letter to a local TV station saying, “How many people do I have to kill before I get a name in the paper or some national attention?”
19. And finally, he considers himself a "natural born predator" and explains his urges by what he calls, "Factor X."
