“Leaf Tanner was shot in this area,” Remy said. “There’s blood spatter on the east wall.”

Remy touched the TV again. “So it looks like he was shot near the door that led in from the courtyard. Then he stumbled across the storage area and into the main art room, where P.T. first saw his body.”

“So we’re assuming what?” I asked. “The science teacher came into the storage area from the courtyard?”

“Hold that thought,” Merle said. “We’re going chronological. We’ll get back there.”

Remy clicked forward, and another kid’s photo came up. Olive skin. Teenager, but a big frame. Could pass for eighteen as easy as fifteen.

“Falls Magnet has a zero period early in the morning,” Remy said. “So if you’re an eighth grader and you go to that, you end up with a free period from two to three p.m. at the end of the day. Meet Easton Pappas.”

“Easton goes to this zero period in the morning,” Merle said. “Which leaves the time between two and three p.m. as his free period. Like a couple other kids, he goes to the art room during that time.”

“Kids paint in there,” Remy said. “Or sculpt. Whittle wood. There’s no class in there between two and three.”

I studied the diagram as Remy continued.

“Now it’s 1:54,” she said. “Harrington’s been on campus ten minutes, and here’s our next account of him. This Easton kid opens the door from the hallway to enter the art class. He looks across the art room and into the attached storage area. Sees Jed Harrington holding a .38 and Leaf Tanner on the ground. Already shot.”

Abe raised his hand. “Wait—Easton opens the door from the courtyard into the storage room? I thought only teachers could do that.”

“No,” Remy said. She walked us through her diagram again, explaining that there were two ways into the art room. The first was in from the hallway. This is how students got to class. The other was through the storage room.

“This Easton kid opened the door from the hallway,” Remy said. “The main way kids go in for class.”

“And what happened next?” Abe asked.

“Easton sees a couple girls working on their canvases. But he also sees through the art room and into the attached storage area. He sees Harrington with the gun. Standing over Leaf Tanner.”

“What’s Easton’s reaction?” I asked.

“He lets go of the door and splits,” Merle said. “He’s the same kid who pulls the fire alarm a minute later.”

“The three girls who got taken hostage,” Abe said. “How come they don’t see what this kid Easton sees? How come they don’t hear the gunshot?”

“They’ve got earbuds in,” Merle said.

“One of them had an early bootleg of the new Zac Brown album,” Remy explained. “They’re all plugged into the same phone and the volume is cranked while they paint.”

“And Easton’s got a vantage point that the girls don’t have,” Merle added. “A straight view into the storage area from the hallway door.”