>> strangled her with my hand. >> reporter: you strangled her? >> reporter: some of the details in that 13-hour interview were almost more even a seasoned detective could stand to hear. >> as he was hurting martha, she told him, i didn't believe in god, but i do now. there is a part of me that's grateful that she found god at the end. it's disturbing to me that in response, he said, you picked a hell of a time to start believing in god. i'll never forget. >> reporter: but she had it -- a full confession. she called jerree's mother, jodi. >> i dropped to my knees. detective trapp gave me her word that she would find who killed my daughter.