Good job Marine!
Even in California he wouldn't be charged, this is pretty clear cut.
I can, however, see a civil case bring brought on by the 17 year old girls family, stating something like "She didn't have a weapon, thus, she was not a lethal threat and should not have been attacked with the same lethality."
While we all know that's total bullshit, you can bet that were it in California, that's exactly what would happen. I doubt they'd win, but it'd still happen.