Sheryl Waldman lived a reclusive life with her sister, Lynda, in their family’s old home. Over the years she faded from view until she vanished, and no one seemed to notice—until one cold evening last December.

What led to the death of a 5-year-old boy, “the Everychild in the state system.”

An investigation into the family of the accused Boston Marathon bombers.

A profile of Tamerlan and Dzhokhar Tsarnaev.