father's .38 caliber handgun. sean didn't know the gun was loaded. >> i was just waving it around one more time and aimed it out the window and as i pulled the trigger, she was running out of the room and unfortunately, it did strike her in the shoulder. >> reporter: so you weren't aiming at your sister. >> no, god no. >> reporter: the bullet traveled to his sister erin's heart. >> immediately dropped the gun and ran and got the phone and called 911 and i picked her up and held her in my lap, you know, as she unfortunately passed away. >> reporter: sean tried cpr, even put pressure on the wound but nothing could save her. she died in his lap. >> i never got to see her in the hospital after they had cleaned her up and everything like that, so unfortunately, the last image i have of her is in my lap. >> reporter: it's become sadly common place to hear about a tragic gun accident like sean and erin so the world including