Dr. Spencer Reid:  There 's something known as the magical age , between nine and _ 12 _ , when a child 's psyche is more malleable . That could be why the UnSub changed his victimology . Like the child soldiers being recruited by the rebels in Sudan , they lack the physical and emotional maturity to resist their captors .
David Rossi: He realized that the younger that he went , the easier they would be to control .