The purpose of trying kids as adults for different crimes at different ages is more of a pursuit for justice. Hell, the human brain isn't fully formed until the mid 20s. If a 19 year old went and shot someone in cold blood, are you supporting him being tried as a kid, or are you just going to tow the line by saying he's over some randomly invoked, arbitrary age?
Maybe I forgot what it was like to be a kid. I was captain of my school's Quiz Bowl team through high school (think of team Jeopardy), which prevented me from playing football. Of course, I was starting varsity pitcher as a sophomore, but that's another story. Sure, I've done stuff to "be cool", but shee-it...if someone told me to go with them to murder someone in cold blood to "fit in", I'd probably do some sort of mix between looking at them like they lost their damned minds, and booking it double-speed to an adult and telling them what they said. High schoolers know right from wrong, for the most part. Now, they may try to rationalize minor bullying, cheating, etc. However, even the most dim-witted teen knows that murder is wrong.Then you must have forgotten what it was like to be a kid. I'm quite sure that at some point in your minority you played the "sheep" to older kids and/or adults you looked up to. It may have been displayed in other forms of bad behavior, hijinks, or whatever you choose to call it...but it likely occurred nonetheless.
Did the particular kid we are talking about pull the tirgger? NO. Did he control the vehicle they were in? NO. Could he have done either? Possibly but we don't know, and not knowing means it is also possible he can be reformed. So again, until I find out more regarding his "priors" I'd say some time in juvie might be just the thing to cure him of his bad actions. If not, by the time he gets out he will be an adult and how to deal with that won't be much of an issue.
If they don't, I think society is better off with them in the ground.