The thing is the motion to be tried as an adult comes before the trial, so it comes before you ascertain anything about motivations, intent, psychological expertise…
I think this whole thing goes with the whole drinking, enlisting in the army, voting… You guys have a legal definition of childhood that’s way fuzzier that I’m used to. In my head, a motivation isn’t mature or not intrinsically, it’s mature or not depending on who has it : if it’s a child it’s not, if it’s an adult it should be so it’s considered as such.
I guess having a hard limit on the eighteenth birthday is weird in its own right… Maybe it’s because I’m old but in my head it should be fuzzy in the other direction: 18 year olds are definitely still kids in most aspects and should get a chance to be tried as children.