Amy Robach tells PEOPLE that Heather Tiffany Robinson "always got an uneasy feeling from [her uncle] growing up" Chris Harris has been a senior true crime reporter for PEOPLE since late 2015.

Last week, relatives testified that Lisa Stasi and her 4-month-old daughter, Tiffany, had disappeared with Robinson on Jan. 9, 1985. But Robinson told investigators at the time that she and her ...