I think there is a lot more to this story than is contained in the newspaper article.
If the homeowner's actions were as bad as the paper and some posters here make them out to be, the police would have arrested him already. Especially, since it happened in Palm Beach, which is one of the most liberal parts of the state.
I would guess that either the homeowner did an excellent job of convincing the police that the perp did something to cause him to fear for his life, or was committing a forcible felony. Or that the police had many run-ins with the "good kid", and knew that he was trouble. Or both.
I don't think the paper necessarily put the homeowner in a bad light. People are naturally fearful of knocks on the door in the middle of the night, and I would wager that most everyone sympathizes, emotionally, with the guy.
But, as a concealed-carry license holder who practices regularly, I know that I must actually be in fear for my life and external circumstances must put me in fear for my life before I use a weapon.
I'm afraid this guy was spooked, but the DA will have to submit the facts to a grand jury to get a judgment. Arresting him or not arresting him at this point may mean that the police don't want to prejudge.
Even in Texas, this situation would likely result in a charge, especially if he shot this kid in the back.
That goes without saying. I NEVER trust newspaper accounts to be complete and accurate. They grab what they have and go to press with it. And they often make things up when they don't have the full details. (A police officer told me that once. I believe it.)
I would guess....the police had many run-ins with the "good kid", and knew he was trouble.
Good thought. Maybe he was a kid that they couldn't pin anything on. You need to get them on video to charge them with anything nowadays.