alleged her brother, bill, had sexually abused her as a child. investigators wanted to know whether this was a possible motive. to see if these entries were written by nancy, investigators sent the diary to a forensic document examiner, hartford kittel. >> handwriting examination's based upon two distinct facts -- no two people write exactly alike. within the writing of a single individual, there is normal variation. it's this normal variation that we associate or we don't associate with the questioned writing. >> surprisingly, nancy and richard's handwriting looked strikingly similar. friends said this was intentional. while in college, nancy had written some of richard's research papers, and she mimicked his writing. kittel first looked at known handwriting samples from both nancy and richard. despite their similarities, there were differences. >> she used her ampersands quite extensively through her writing,