Do the police fire "warning shots"??? No.
Ever wonder why? Because what goes UP must come down and "warning shots" will come down somewhere possibly injuring or killing someone or damaging property.
Most folks I know would NOT fire a warning shot, they may give a verbal warning but if they are pushed to the point of firing their weapon they will shoot to kill. If they have to fire the negotiations are over.
You're comparing apples to oranges. The homeowner is NOT a police officer.
Police officers are specifically trained to handle ambiguous situations such as these. The homeowner is NOT.
Furthermore, you as a private armed citizen are supposed to use "reasonable force" against an aggressor only in cases of self-defense, not excessive, deadly force to kill someone who was obviously NOT committing any crimes against you or your property.
Unless the group of people who had driven onto your property posed a reasonable threat to you/your property, or the foreign exchange student had acted in such a manner as to have physically threatened you or your property, you have no right to shoot to kill.
I believe in use of comparable force against antagonists. The homeowner, if he felt threatened, should have stayed inside his home and called the police, not run outside to confront what he considers dangerous criminals by shouting out "Shut up!" and over-extend himself by fatally killing innocent people.
Sorry, any way you look at it, the homeowners were DEAD WRONG in the case discussed in this thread, as well as the Baton Rouge case, and in both, innocent people were unjustly murdered.