LITTLE FALLS, Minn. — The day after a Minnesota man killed two teens who entered his home, he matter-of-factly described the shootings in chilling detail, telling authorities he finished off one teen with a shot under her chin because a .22-caliber "doesn't go through bone very well," according to an audiotaped interview played in court Monday.

Byron Smith, 65, of Little Falls, is charged with first-degree premeditated murder in the slayings of 17-year-old Nick Brady and 18-year-old Haile Kifer on Thanksgiving Day 2012. The killings rocked the small central Minnesota city of about 8,000 and stirred debate about how far people can go in defending their homes.

Prosecutors said during opening statements that Smith planned the killings and was lying in wait in his basement. Smith's attorney said his client was terrified after several increasingly violent break-ins and was hiding after he heard a window break and footsteps upstairs.

"He became frightened and scared to live in his own home," said Smith's attorney, Steve Meshbesher, later adding, "He began to wear a holster and pistol in his own house. That is how afraid he is, and became."

Assistant Washington County Attorney Brent Wartner told jurors that Smith thought a neighbor girl had been breaking into his home. On that day, he moved his truck away from his house, sat in his basement "and he waited," Wartner said.

"He's down in the basement, in a chair, tucked between two bookcases at the bottom of the stairs. He said he was down there reading a book ... with his Mini-14, a .22-caliber revolver, some energy bars and a bottle of water," Wartner said.

Byron Smith

Under Minnesota law, a person may use deadly force to prevent a felony from taking place in one's home or dwelling, but authorities have said Smith crossed a line when he continued to shoot the teens after they were no longer a threat. The teens were not armed, but Smith told authorities he assumed they were — and he thought they had taken guns from his house in a past burglary.

In the recordings, Smith can be heard politely recounting details to investigators. As the recordings were played Monday, Smith sat still at the defense table, at some points crying.

Smith told Morrison County Sheriff's Sgt. Jeremy Luberts that he was in his basement when he heard someone rattle his door, followed by footsteps on his deck and a shadow in a window.

"I'm getting seriously stressed because somebody wants in," he said. After a moment of silence, he said he heard a window break, and footsteps inside.

Smith told authorities he saw Brady begin descending the basement steps, then fired once Brady's hips came into view. Brady fell.

"He's looking, facing up at me, and I shoot him in the face. I want him dead," Smith told investigators.

Smith said he put Brady's body on a tarp so he wouldn't get blood into his carpet, dragged it into his workshop, reloaded his rifle and sat down.

Smith described feeling adrenaline, and "blood was pounding in my ears." He said he also felt he was being ganged up on, something he called one of his "red buttons." So when he saw Kifer come down the stairs minutes later, "I killed her too."

He shot her, and when he tried to "finish her off" his rifle jammed and she laughed, he said.

"I just pulled out the 22 and I shot her," he told authorities. He said he then pulled her into the workshop, but she was still gasping, so "I did a good, clean finishing shot and she gave out the death twitch."

He said he didn't call police because the teens were already dead and "just cause my Thanksgiving is screwed up I don't need to screw up yours." The next day, he asked a neighbor to call police.

Smith is a retired security engineer for the U.S. Department of State. Kifer and Brady were cousins. The two were well-known in the community, and both were involved in sports.

Court documents from another case show Brady had burglarized Smith's property at least twice in the months before he was killed.