the brother who bought robert john bardo the gun after bardo was turned away. >> his siblings actuallyoset? >> i believe i did. >> did you ever see the gun again? >> no, i didn't. >> the fact that he got his brother to help him buy a gun, these were all ways in which to prove that he was actually thinking about killing. >> several other members of robert bardo's family took the stand, including his father, phillip. >> we happened to be watching the cnn news, and i heard that rebecca had been killed. and my first thought was that we couldn't believe it. my son went and checked to see if the pistol was still in the house, and the pistol was gone. >> a neighbor would describe the sound of the weapon that killed rebecca schaeffer. >> i dropped to my knees because the blast rattled the door and sort of knocked me to my knees. and i heard the scream, one very loud, long scream. >> in an effort to prove that bardo is mentally ill, his lawyers call to the stand park dietz, a forensic psychiatrist who's no stranger to a courtroom. >> now, dr. dietz testified in the unabomber case. he testified