mary taglianetti (on phone): ok, i'm sorry. dennis murphy (voiceover): her name was mary taglianetti. she was calling from virginia. no one in keith reed's life, including his daughter, megan, had ever heard of her. that name mean anything to you, this mary woman? not at all. anybody in the family, did it ring a bell? no. dennis murphy (voiceover): megan's older sister, katelynn, didn't know the name either, but would soon realize this mary was a woman her dad had taken to dinner back in 2010 during an off period with kimberly. i remember him saying that he was going out to dinner, but yeah, no, nothing ever came from it. dennis murphy (voiceover): but now this mary was on the phone. she was very, very upset. mary taglianetti (on phone): [crying] joe gerace (on phone): stay with me. this is going to be ok. relax. joe gerace: i kept her on the phone purposely as long as i could. and while we were talking, i had my staff scrambling to get somebody in law enforcement to her home. dennis murphy (voiceover): almost 400 miles south,

and she said, sheriff-- mary taglianetti (on phone): [crying] joe gerace (on phone): stay with me. --you have a phone call i think you need to take. hello, and welcome to "dateline." keith reed was a school superintendent who was respected by his students and adored by friends and family. when he didn't show up at an out-of-town conference, it set off alarm bells. investigators would take a hard look at keith's love life for clues. and it would be another person off everyone's radar who would help detectives piece together this puzzle. here's dennis murphy with "at close range." dennis murphy (voiceover): winter comes early and stays late in far western new york. the farmlands near chautauqua lake, tilled by amish and dutch families, are encased in snow and ice for months at a time. but in this place of frozen stillness, the hottest of passions, boiling jealousy, came to call one day. and tiny clymer, 1,700 residents in the southwest part of the county, is still shaking off the shock of it all. joe gerace was the sheriff of chautauqua county. my 35 years in law enforcement, can you