You worked with the police as a consultant detective, just like Sherlock. While he was doing this because of the boredom and for adrenaline, this job was for you just a cover. You were a serial killer that nobody managed to catch. Even Sherlock had no clue about you, "The Killer of the Westminster", you lived in the constant fear of being caught, but perhaps you just enjoyed that thrill.

In the night, you committed another murder and in the morning, you and Sherlock were called in the scene crime. He started to do his usual analytic reasoning, and then, looked at you.

"Any guesses ? It's obvious the Killer of the Westminster did that..."