38-year-old Sara Bermudez and her three children, Madison, 8, James, 6, and Michael, 2, are viciously attacked in the middle of the night while they sleep. The murdererSexually assaults Sara and her 8-year-old daughter, with a knife and stabs the family to death before setting them on fire. Sara's father finds the carnage and calls for Help. Investigators catch a break in that the killer tried to use diesel to fuel the fire but it burned itself out before totally destroying all the evidence.Joseph Scott Morgan is going to take you inside the master bedroom and explain how investigators find a suspect from a portion of body fluid left behind at the scene. And the suspect isn't just close to the family, he is family. 

Transcript Highlights
00:00.96 Introduction - chewing and identity
04:20.45 Somebody breaks into a home in the middle of the night Slaughters the mom, daughter, two boys
09:20.18 Family murdered and set on fire
14:12.60 Disturbing element to the case 
18:12.07 Setting up a line to prevent contamination
22:57.18 Evidence of sexual assault
28:07.64 Knife used in sexual attack
32:56.90 Blood stains found on walls, carpet, lamp, other items
37:12.63 Finding blood in the fire
42:00.92 Mother defended her children
44:58.66 Conclusion