Some of us have interesting reasons to pick a detective name. What is yours?
jstkdn which some people don't realize right away stands for JuST KiDding! It is something I tend to say a lot in real life after a lot of sentences. A good friend of mine in the US had jstkdn as a license plate of her car, so I wasn't that inventive myself.
My previous other agent was PM, which stands for Project/Program Manager, my profession in real life.
My only detective that I currently play with is freelancermountaineer. Only because Freelancer was taken. Sidney Bristow in the Alias series uses two call signs freelancer and mountaineer.