By CATHY FRYE

Arkansas Democrat-Gazette

Thomas Cogdell, 12, struck many residents in small-town Camden as quiet and well-mannered, the small possessor of a considerable intelligence that often startled his teachers.

He lived in a little gray house on Waco Street with his single mother and 11-year-old sister, Kaylee.

Neighbors say Thomas spent much of his time reading or playing video games. He sometimes offered to do yardwork, hoping to earn a little money. And he was protective of Kaylee, who acted younger than her age.

Neighbor...