You've said this multiple times but you're wrong. The First Degree Murder Statute has nothing to do with "premeditated".
True. Louisiana's first degree murder statute is built around a specific list of aggravating factors that would elevate a murder to first degree. Most of them have to do with the identity of the victim--elderly, child, law enforcement, etc. I'm pretty sure Tahj doesn't fit any of those descriptions.
Some have to do with what else the killer may have been doing at the time--certain crimes such as specific enumerated crimes like kidnapping. As far as we know, this situation won't fit any of those either.