She asks why Speedle's focusing on pants and not shirts, and Speedle replies that "any spatter from a vic is going to be lost among the primary." Calleigh counters that it's hard to get spatter from a long-barreled shotgun. Speedle sits bolt upright and says, "Unless we're not looking for spatter." Calleigh checks the lens and notices several neat round dots of blood. She says, "That's transfer." Speedle recognizes the pattern: "That's tread, from the toddler's footies. The question is, whose blood is it?" Cue Horatio coming downstairs to get results from Speedle; Speedle tells him the transfer stains on Luke's pants come from Stephanie. We go into Horatio's voice-over as we flash back to the scene: "Instinctively, he picked up the toddler, thinking the killer might still be in the house. He did it after Mom was mortally wounded." That Luke had some serious presence of mind; it's not every kid who'd walk in on his mom with half her face blown off and immediately think of protecting his kid sister. Horatio wheels off, presumably to launch a group meeting. Speedle tacks up Exhibit A: The Dirty Dishes, and says, "Mom and Dad aren't doing their jobs, so the son steps up to the plate." Horatio adds, "Luke tries to bring his siblings lunch and walks into a massacre." Delko asks, "Once Luke's in the room, why not save the infant? The swing and the bassinet were in the room." Calleigh says, "Judgment call -- who can imagine shooting something so small?" Megan adds -- NOTHING! She's not here! It's as if the minute the news about Kim Delaney's departure broke, a team of editors was called in to begin excising Megan from episodes. It's pleasant -- no more typing [beat] all the time -- but somewhat unsettling. I imagine old Soviet ministers looking at group pictures from which coworkers had been erased might know the feeling. Horatio speaks next: "While Luke is saving the toddler, the killer goes after his next threat: Timmy." Delko comments, "Nine-year-old boy -- some threat." Speedle says, "Luke comes back in, tries to save the infant." Horatio continues, "But he dies trying to get the infant out the front door, and why does that happen?" Delko says, "Dad's blocking his path." Horatio counters, "Dad's been shot in the back, and his wound is not self-inflicted." Calleigh and Speedle suggest that Jason and Luke struggled over Max, and in the contretemps, Luke managed to shoot his father in the back. This is more or less confirmed when they look at Max's little romper and notice three small gravitational droplets of Jason's blood, which means that Jason was hovering over the baby.