. >> we, the jury find the defendant, david martin hawk -- >> held loech hello. welcome to "dateline." when someone goes missing, one of the hardest things for those left behind is not knowing the truth. was is voluntary or foul play? it the three children in this story arrived home one evening to discover their mother was missing, but for them, the truth about what really happened may have been the hardest thing of all. here's keith morrison. >> the key was waiting for them under the mat that evening in june 2006 outside their mom's house, silence, no one home. with are was she? she was always on time to pick them up from their dad's place. but tonight he had to drive them. this just wasn't like her. where was she? convad, the eldest put the key in the lock, opened the door. chelsa, in the middle stopped. >> once we took a few more steps in, we realized there was something wrong. >> this was the moment, the defining one. nothing the same after this. >> there was a lot of blood. everywhere. >> then the adrenaline kicked in. instinct took over. >> we just dropped