Jurors in a Minnesota trial heard a chilling audio of a killing Tuesday made by the shooter himself. When coupled with other evidence, prosecutors believe it  shows the accused  homeowner was lying in wait to kill, not acting in self-defense against intruders.

In it, Byron Smith, 65, shoots and kills 17-year-old Nick Brady and 18-year-old Haile Kifer on Thanksgiving Day in 2012 after the teenagers broke into his Little Falls home. He says he was frightened, hiding in his basement, on edge after earlier break-ins. He feared the two were armed, which they weren’t.

Smith is in the basement when the recording starts.

It begins with the sound of glass shattering, followed by footsteps on the floor above.

Then there are two gunshots.

Brady falls down the basement stairs. “You’re dead,” Smith tells him, according to the Star Tribune.

Prosecutors allege Smith shot the teen a third time in the face and later told investigators, “I want him dead,” ABC News reported.

Almost immediately after the first shooting, the rustling of a tarp is heard, then a dragging sound and labored breathing. Smith said he had moved the boy’s body to a workshop in the basement to keep his blood from staining the carpet, the Associated Press reported.

The audio continues with the sound of a gun being reloaded. About 11 minutes pass between the two shootings, local reports say.

Kifer’s footsteps are heard on the stairs and she calls out quietly, “Nick?”

Then comes the sound of more shots. She falls down the stairs. “Oh, sorry about that,” Smith tells her. She screams, “Oh my God!”

Then more shots. Smith tells her, “You’re dying,” and calls her a “bitch,” the AP reported.

After more labored breathing and another dragging sound, Smith calls her “bitch” again. He told authorities that after he moved her, he noticed she was still gasping and didn’t want her to suffer, so he fired under her chin with a 22.-caliber handgun, according to a report in the Pioneer Press. The Star Tribune reported Smith told investigators the last time he fired was “a good clean finishing shot” and “she gave out the death twitch.”

The Bureau of Criminal Apprehension investigators on Tuesday detailed the evidence, including photos of the bodies: “Brady’s laid tangled in a camouflage tarp, Kifer’s laid with her bloody midriff exposed, knees bent, a black hoodie tied tightly around her face,” the Star Tribune reported.

Prosecutors said during opening statements on Monday that Smith planned the killings and was waiting in his basement with loaded weapons, some energy bars and a bottle of water. Smith allegedly had the audio recorder, part of an elaborate surveillance system, running for six hours before, during and after the shootings. Smith’s attorney argued his client was terrified after several violent break-ins and he hid after he heard a window break and footsteps upstairs.

When questioned about why he had continued to shoot, Smith said he didn’t want to wait for them to pull weapons, The Star Tribune reported.

Smith said he ended up hiding in the basement through the night before calling a neighbor the next day because he was afraid of an accomplice.

Smith was initially charged with second-degree murder, according to early news reports. The first-degree murder indictment came last year after a grand jury spent two days reviewing evidence and listening to testimony. If convicted of first-degree murder, he could face up to life in prison.