bill says to him, "look, you don't need a search warrant. go. carte blanche, go in that office. take whatever you want. i don't care. i'm an open book." narrator: analysts dismantle the typewriter, which only four people had access to -- bill and mary yoder, adam yoder, and the office receptionist, kaity conley. scotti: the examination of the typewriter ribbon really went back to old-school police work. vannamee: the cartridge was taken apart, and the used ribbon was cut into approximately 2-to-3-foot lengths and placed on a white posterboard, and you could actually read every keystroke that that typewriter had made. narrator: and those keystrokes showed the addresses of the medical examiner and the sheriff's office -- the destinations of the anonymous letters. this proved the envelopes that contained the letters implicating adam yoder had been typed on this machine. 22-year-old kaity conley was confronted with this evidence