Trail of Blood. Wanda Evans

When Jim Dunn got the heart-stopping call every parent dreads: «Your son has disappeared,» and then saw his son's blood-splattered apartment, it set into motion a six-year nightmarish odyssey of desperate searches. Ahead were moments of frantic hope, growing despair and finally acceptance that Scott was dead. Texas law insists on a body before prosecuting anyone for murder and Scott's body was nowhere to be found. Frustrated, Dunn turned to members of the little-known Vidocq Society, highly experienced criminologists and forensic experts who crack the coldest «unsolvable» or unprovable" cases around the world.