aaron candelario and shannon palmer were young and in love and engaged to be married. but their family was rocked by scandal. then murder. aaron's father was found at the crime scene dazed and confused. but his confusing story had police questioning his version of events. here's keith morrison with "tangled." >> you can't put words to that. it was very surreal. >> 911. where is your emergency? >> it's true, the old saying, when you marry someone, you marry their family, too. >> we need an ambulance. he looks like he's been shot. he said someone broke in last night. him and his wife both. >> not a bad thing to turn to mom or dad for advice and counsel. >> it's hard. sometimes you think maybe it didn't happen. but yet it really did. >> it's with their help and support, after all, that true love could deepen and grow, and last. >> i watched the crime scene shows on tv. i never, ever thought, it's going to be my life. >> yes, it really is all about family. the high desert opens up near pueblo, colorado, about 100 miles or so south of denver. among the highest of the nation'

. >>> the year was 2004, and aaron candelario was 11 years old.is parents had recently separated, were sharing custody. and one day, after a weekend at his dad's house, aaron went home to find -- >> there was just a note on the coffee table that was in kind of sketchy handwriting. but it, you know, nevertheless said, "i love you, my boys, and i'm taking off." >> reporter: his mother dena was simply gone. aaron was devastated. what did your father suggest may have happened to her? >> that she possibly had moved to missouri. a guy that she had been talking to online for quite some time, you know. maybe she ran away to be with him. >> reporter: a missing person's case was opened, but nothing came of it. aaron and his brother moved in with ralph full-time. but aaron couldn't move on. she had to have left some trail somewhere. barely a teenager, he taught himself every web search engine. looked for years, but found no sign of his mom online. and a terrible suspicion took hold of him, hardened into something like certainty. his mother must be dead. his