but detective peglo was no rookie. his investigation into charlie tan and what happened inside that home was just getting started. >> one of the investigators found what appeared to be newly taken passport photos. along with a list of prominent local defense attorneys. >> that's interesting. >> yes, sir. >> the story is, i had to do it, but you're not taking it at face value. >> correct. >> coming up, a discovery on jim tan's computer triggers suspicions about his time of death. >> how many days prior is the last e-mail check? >> four. that was really a big thing for me. >> when "dateline extra" continues. alzheimer's disease is out there. and the alzheimer's association is going to make it happen by funding scientific breakthroughs, advancing public policy, and providing local support to those living with the disease and their caregivers. but we won't get there without you. visit alz.org to join the fight. hmmmmm....... [ "dreams" by beck ] hmmmmm... the turbocharged dream machine. the volkswagen golf gti. named one o

detective steve peglo of the monroe county sheriff's office. >> charlie told the deputy he was upset and he came home to talk to people and he was just working out some things and he would be okay. >> it was now late thursday night, almost the weekend. charlie didn't go back to school friday morning and come monday he wasn't at practice. >> there wasn't much i could do other than text him and he didn't respond. >> and then it was monday night, something awful. >> 911, what is the address of the emergency. >> yes. hi. >> the call sore distraught confused the dispatcher. >> my name is jean tan. i just -- i heard an argument and my -- my son was talked to my husband. >> ma'am, i can't understand >> it was jean tan, charlie's mother. >> did you say you heard a shot? >> yes. >> does somebody in the house have a gun? >> now the garbled story was coming into focus. shots fired, the husband, the man of the house was dead. >> my husband is dead. >> who's already dead? >> my husband. >> your who? >> my husband. >> are you in a safe spot? >> yes, i am. >> we need you to wait outside of the hous

but detective peglo was no rookie.nvestigation into charlie tan and what happened inside that home was just getting started. >> one of the investigators found what appeared to be newly taken passport photos, along with a list of prominent local defense attorneys. >> that's interesting. >> yes, sir. >> his story is i had to do it but you're not taking that at face value. >> correct. >> coming up, a discovery on jim tan's computer triggers suspicions about his time of death. >> so how many days prior is the last e-mail check? >> four. that was really a big thing for me. >> when "dateline" extra continues. >>> welcome back to "dateline extra." police arrived at the home of jim tan to find him lying behind the desk in his home office, shot dead. his son charlie told police he did it. he said he was defending his mother. so, case closed. far from it. let's return to dennis murphy with "house of secrets." >> deputies canvassed the neighborhood but no one had heard the gunshot blast that the son admitted moments after deputie