Science & Tech

Determining M.O. vs. Signature: The BTK Strangler

John Douglas

Lesson time 17:25 min

John discusses the BTK Strangler, a serial killer who sent taunting letters to the police and media. In this lesson, John explains the differences between MO and signature so we can determine whether others are interfering in our lives.

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Topics include: What is M.O. vs. Signature? • Case Study: The BTK Strangler • Profiling BTK • Identifying BTK’s M.O. and Signature • Outsmarting BTK • Interviewing BTK • Recognizing an M.O. and Signature in Others • Assignment


- I have many, what I call them, projects. They were different people in the town that I followed, watched-- potential hits. In my world, that's what I call them. [SUSPENSEFUL MUSIC] Some cases really bother you because you want to help, you want to solve these cases. But someone goes years, we don't hear from them. And all of a sudden, they pop up again and then the cops are calling you. And one of those cases was the BTK Strangler out of Wichita, Kansas, which I'll use to teach the difference between MO and signature. When you're profiling serial killers, you're looking for an MO to link cases together. You hear on television today, the word MO. If you read in a book, MO means modus operandi. What I found with modus operandi, it's something that can be shaped. It's learned behavior. And so therefore, as learned behavior, don't expect to be able to link cases together by modus operandi alone because the subject is learning from previous mistakes. NARRATOR: For example, a novice burglar who shatters a basement window during a robbery may next time bring a glass cutter or tools to force open the door, thus making less noise. So the MO continuously evolves as the burglar gains experience and confidence. - So there's another step that we're going to be looking at, would be the signature. And what the signature is, is ritual. It is something that the subject needs to perpetrate the crime. It may be torture. He may be a sadistic offender. He may decide his ritual is to pose the body, stage the bodies in a particular way. It's almost like a habit, a habit that he's formed. And he can't, or she can't, really break it. It's like looking at a baseball player getting ready to bat. Takes a pitch, it's a ball. He steps out of the box, rubs his hands, opens up the batter's glove, wipes this brow from his head, hits the bat on the home plate a few times, and then steps back in the box. That is really unnecessary for him to hit the ball. But he feels if he doesn't do it, it's kind of like bad luck. NARRATOR: Around 1984, investigators from the Wichita Police Department reached out to the FBI for an analysis. A decade earlier, the Otero Family-- a husband, wife, and two of their children-- were killed by an unknown perpetrator. - These victims died either of ligature strangulation, which is by garrote, or manual strangulation, using the hands. In '84, they had much more information. There were more homicides. What began to happen is that he began communicating with the media. He came up with the BTK, for the bind, torture, kill. He wants to be this well-known killer that's putting the fear of God in the city. So he's really getting caught up with that. And he's writing more and more of these communications. It's also given him confidence, where he's now killing more frequently and communicating more with the local police. He's going to be a white male. NARRATOR: His victims were...

About the Instructor

Netflix’s “Mindhunter” was inspired by the FBI’s first criminal profiler, John Douglas. As chief of the National Center for the Analysis of Violent Crime, he conducted groundbreaking interviews with notorious criminals such as Charles Manson and Ed Kemper, changing interrogative tactics forever. On MasterClass, he teaches you to use his methods in everyday life, unlocking your intuition to read people's motives.

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John Douglas

Legendary Special Agent John Douglas teaches how criminal profiling methods can help you predict people’s motives to benefit your everyday life.

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