Yet Another Daydream of Walter Mitty

..."Could the killer still be here?" whispered Deputy Walter Mitty.
"Heavens, Jack, look at this!" cried Mitty as they entered the doorway. There was a woman lying on the floor in a pool of blood. She was obviously dead. The neighbor had told the dispatcher that the woman lived with her two small children. He had seen the kids in the front yard nearly every day. Now that they had found the mother and one child, they needed to find the smaller child, but they didn't know if the killer was still lurking in the house.
While Jack went up the stairs, Mitty searched the first floor. The dread…