you don't know who he is. you know it's somebody that you don't know. and they have crossed that invisible line from outdoors to indoors. and they are, by that definition alone, i would say, a threat to me. >> well, you've got to be able to articulate the threat. >> reporter: and kaarma told investigators there was a real threat. the garage was full of tools the intruder could grab and use against him. >> i imagined an ax flying through the air and hitting me in the skull. >> reporter: and kaarma said he was positive he heard that scraping sound just moments before he fired the shotgun. >> i'm describing the sound when i say it hit -- >> okay. >> but what i'm picturing in my head is i'm going to die. >> reporter: to hear markus kaarma tell it, he'd faced down a threat. it was kill or be killed. and that was justifiable homicide. the young soccer star who was by now in the morgue must have had a darker side that many didn't see.