Reporter his fellow cops suspected him i did not do this. I did not do this reporter she was upset. She felt like history was repeating itself. He wanted to have women and his wife was getting in the way. Were police just plain wrong . Its like this Twilight Zone where lies become truth and the truth becomes lies. Reporter maybe the real killer was still out there. You have lied to the police about this case. Yes, sir. So devastating. We knew that that was probably the key to solving this. Thirteen years. Thirteen years of hell mystery on lockhart road. Hello and welcome to dateline extra. Im craig melvin. David came home one evening to find his entire world turned upside down. What happened in the family garage was both a tragedy and a mystery. At the crime scene, police uncovered clues that would lead them on a long road to justice. There were two potential killers. But only one truth. Here is dennis murphy. Reporter such an awful crime. The wife. The little boy and girl. My kids are
welcome back to dateline extra. they had been his coworkers. some his friends. police interviewed him with care in the first time around but they were about to bring him in again and this time the move would be decidedly different. here again is dennis whitman. reporter: in the days after the murders, two families, the lockharts, uncles, aunts, nephews, nieces, and kim s family were united in grief. we lost three wonderful people that we loved dearly. we don t have them with us today. kim, bradley, jill, just like that. gone. all gone. reporter: david was all but shutting down. i m a mess. i m on medication. you know, i m having to buy