JoshuaZ admitted it during an arbitration interrogation over his sockpuppets, but it has never been altered from Gastrich to JoshuaZ. It still carries the innocent Gastrich's name.
I mentioned to Jayjg and Jimbo before there have been three accounts used by me previous. User:Rookwood was before I was an admin when I needed a fake individual to get in Jason Gastrich's good graces. User:CyberDalek was made with a similar idea in mind by me and Will Beback but it never got off the ground. I made a third account a long time ago so that if I ever needed to vanish I could resume editing with an account that would have had some prior history (the account had maybe a handful of edits 2 years ago, and I don't recall its name unfortunately).