Byron Smith could have testified in his own defense on Monday, but he waived his right to appeal directly to jurors and remained silent.

The 65-year-old Little Falls man and his legal team may be regretting that decision today, but many Minnesotans — including the 12 men and women on the jury — had already seen and heard too much from Smith.

In a case that reignited the national debate over self-defense, the former State Department security specialist was convicted Tuesday of premeditated murder in the shooting deaths of 18-year-old Haile Kifer and 17-year-old Nick Brady.

Smith's lawyers, who say they will appeal the verdict, had made their client out to be a third victim, arguing that he was justified in shooting the unarmed Kifer and Brady on Thanksgiving Day 2012 because he was terrified by previous break-ins in which guns were taken from his home.

In fact, jurors heard audiotaped police interviews in which Smith calmly told authorities that he had assumed the intruders were armed, making it a shoot-or-be-shot confrontation.

But the jury heard other recordings, too, and no doubt those weighed heavily during their deliberations. Smith, who had set up security for embassies while with the State Department, recorded audio of the shootings and the aftermath. In a case that tested the limits of the "castle doctrine," he had wired his own castle.

For many who followed the case, the recordings provided all of the evidence necessary to conclude that Smith had planned the execution-style killings in retribution for the break-ins.

Smith waited in his basement while Brady and Kifer entered the home upstairs. The recordings capture the sounds of two gunshots and Brady's groan, followed by Smith firing a third time before saying, "You're dead."

Smith later told investigators that he moved Brady's body to a workshop because he was worried about blood on his carpet — not exactly the kind of practical thinking one would expect from a break-in victim beside himself with fear.

About 10 minutes pass on the recordings before Kifer comes down the stairs while calling out for Brady. More gunshots can be heard — followed by Smith saying "Oh, sorry about that" — before Kifer cries out, "Oh my God!"

Prosecutors said Smith used two guns and fired nine shots. His last recorded words to Kifer are, "You're dying … bitch." He can later be heard saying, presumably to himself, "I don't see them as human. I see them as vermin."

The Morrison County jury had to decide whether Smith acted as a reasonable person would have under the circumstances. Under state law, homeowners can take a life in self-defense if they fear death or great bodily harm or if they are acting to prevent a felony.

Jurors in the Smith case were told to weigh whether he perceived the gravity of the situation in a reasonable way and whether his decision to shoot was reasonable given the danger.

For obvious reasons, there are limits to the "castle doctrine," and Smith crossed the line between a reasonable self-defense and premeditated murder. It took the jury just three hours to return the verdict.

"This was a case about where the limits are," Sheriff Michel Wetzel said at news conference after the verdicts were read.

Brady and Kifer broke the law when they illegally entered Smith's home, and they deserved to be arrested and prosecuted. But there was nothing even remotely reasonable about the nine shots Smith fired on that horrible November day in Little Falls.