He joined the other students in the cafeteria, and soon they were in a line and on their way to class. In the back, Tyshaun dragged his feet and ran his hand across the wall.

Nikki Lee, his teacher, put her arm around him. “You’re getting frustrated again,” she said as they walked.

Tyshaun had struggled with controlling that exasperation before, but he’d made progress in second grade. In his electric-orange Adidas backpack was a sheet Lee used to rate students’ behavior from 0 to 6. “Great job,” Lee had written below a 5 a week before the shooting. He got a smiley face below another 5 two days before it and another 5 on the day it happened.

Whether his mood that morning related to his father’s death, she didn’t know, in part because he had never discussed it with her. But Lee understood how what her kids endured in their homes and neighborhoods could cripple their ability to succeed in school. On that day alone, she would manage a girl who stormed out in tears, a boy who slammed his chair against the floor and another who purposefully knocked his head against a desk as he muttered, “I’m going to hurt myself.”

Tyshaun did little more than lay his cheek against his forearm.

Now it was almost 11 a.m., lunchtime, and Lee asked if he could open the door, his official classroom job.

“Are you ready to fix it?” she said, and Tyshaun nodded that he was.

He held the door and the class marched down the hall, where he held another one. A girl approached him.

“Did your father die?” she asked, and he sensed a trap.

“Shut up,” he snapped.

Another boy laughed and motioned in his direction.

Tyshaun’s fist tightened into a ball.

“I’m going to smack you,” he said, but before he could, Lee intervened.

She called the other child over as Tyshaun explained what had happened.

“Tyshaun thinks you were laughing at his situation,” she said.

“I didn’t laugh at him,” the boy said, but Tyshaun didn’t believe that.

Fuming when he arrived at the cafeteria, he asked a woman at the door if he could see Mr. Murray, his favorite teacher. She told him he needed to wait. Tyshaun’s jaw clenched. He walked away, then turned back and screamed.