Family members and others gather following the unveiling ceremony for the mural in Washington. (Bonnie Jo Mount/The Washington Post)

The paint on the wall was barely dry when a teenage girl stepped up to the mural of faces — young faces, brown faces — and lifted her arms to brush the cheek of a boy who was killed before he turned 15.

They were elementary school classmates, she said, so she came to the wall to honor him. She came, she said, to honor all of them.