No information about the rifle, but it definitely did the job

The Wagoner County Sheriff's Office said the homeowner and his adult son were in the home when three males wearing masks and gloves tried to break in at about 12:30 p.m. The homeowner's son shot the intruders with a rifle, deputies said, killing all three.
So they were armed, masked, and did this in broad daylight; sounds like they were planning or just willing to hurt anyone they found inside.  Barring something else turning up in the investigation, I doubt the rifleman has to worry about charges.

Added: this story says an AR-15.  Y'know, one of those EBRs we're told are useless for self-defense.