>> for darlie's defense, mulder called two doctors. one who thought she was suffering from amnesia and another who thought the wounds had not been self-inflicted. they also focussed on the 911 call from the night of the murders. [ screaming ] >> the 911 tape, when i heard it, i was very convinced that she was a hysterical mother. but all of a sudden, darlie was worried about touching a knife. >> there's a knife? don't touch anything. >> i already touched it. >> it's okay. it's all right. >> what grieving mother would even think of that. she went from being a victim in their eyes to a murderer of two little children. >> finally, prosecutors showed a video shot after the murders. ♪ happy birthday to you >> for some, this may seem a