He parked his truck several blocks away and turned off all his lights, because he was sure the intruders only entered homes they were certain were empty of people. He also bought tarps to use as shrouds before he moved his truck.
He rearranged the furniture in his basement so he could fire from concealment, and he stayed in his hiding place with his cameras, food, drink, and reading material for at least six hours.
While he was waiting he had audiotape running, in which he could be heard practicing what he would say to the police and to his lawyer.
He had the intruders under video surveillance before they entered the home, and watched them for a long time searching for valuables, which he had already secured down in the basement.
He did not call the police.
When the first teen came down the basement stairs, he fired at him from cover. After he went down, he walked over to the gutshot teen and said calmly: "you're dead" and then fired a killing blow. Then he wrapped him up in a tarp and hid his body in the next room, went back to his hiding place and waited for the girl.
When she came to the top of the stairs and called the boy's name, he shot her and she fell down the stairs. He walked up to her and calmly said: "Oh, so sorry about that." Then he shot her twice more in the chest.
Then he wrapped her up in a tarp while she was still breathing.
He went into the next room and got a new weapon, and then took a minute to place a gun under her chin and whisper abuse to her before he finished her off.
Then he made himself some dinner, watched some TV and went to sleep. The next morning he got up, went about his usual routine and asked his neighbor if he knew a good lawyer.
His neighbor called the police, not Smith. He just sat there with bodies in his house for over 24 hours.
Facts not allowed by the Judge. Nor was the police's "non-response" to previous robberies of his house.
Every case stands on its merits and this guy is a murderer (and probably a bit insane). My point is more along the lines of using lethal force in defense of your property is a right.