david tronnes killed shanti cooper. he intended to do it.he state's case is the forensics. >> if she was there as he describes, left side submerged, how does her right arm get into rigor straight up in the air? >> deborah: in the courtroom every day, 13-year-old jackson cooper, determined to get justice for his mom. >> and who is it that's not breathing? >> my wife, my wife, shanti. >> the strength that jackson had to sit there and say, "i'm going to be here for my mom," it was the most awe-inspiring thing i've ever seen in the practice of law. >> deborah: how hard was that for you? >> i was just thinking, that wasn't my mom. the stuff that they described, the pictures -- the pictures that i saw, that wasn't her. >> deborah: so you were able to distance yourself? >> yeah. >> we knew that something drove the attacker, that we know as dave, to such levels of violence. so, jurors want to know why could somebody do something this bad? the state focused on the home renovations and what sort of stress that that caused. >> deborah: to make their po