Got it, Mello2u. The article represents a low standard of journalism because it doesn't answer all the questions you have.
It is interesting to look over various historic events, criminal reports, etc. and come up with questions not addressed they way we would have liked, or in the reporter's/officer's presentation of information to answer certain questions, we are spurred to consider additional questions which are not answered. That is a kind of nature of the beast. Only you can come up with answers to all of your questions and regardless of how thorough somebody else reports information, there are always going to be questions.
Did you notice from the article that there is still an open investigation? The lack of information you want isn't necessarily the fault of journalists either. Law enforcement has a long history of only repleasing limited information and sometimes repleasing incorrect information. This is especially true of open cases.
The article did answer who, when and where; but in my opinion failed to answer what and why.
What was the weapon used to defend the home?
Why did the sheriff's department decide this was a justified shooting?
Once again, the weapon used was a .22 rifle. The the information isn't sufficient to support your assault weapon agenda probably isn't a concern of the police, reporter, or others.
As for why the sheriff's department considered the shooting justified, I don't understand what it is that you are clear on in this matter? You have a forced entry home invasion by multiple people and the renter's son shoots and kills one of the invaders and you don't know what it is justified?
Of course you could have looked at the article and noted that it was days old when posted here. You could have simple pulled out some of the key words such as the names mentioned in the article and Googled them or searched the same newspaper to see if there was new information. You might have been surprised by some of it. For example...