The former executive assistant of accused Long Island serial killer Rex Heuermann is speaking for the first time exclusively with Eyewitness News.Donna Sturman told investigative reporter Kristin Thorne she still has not gotten over the shock of the claims made against her former boss."It's traumatizing," she said. "It's so unbelievable."Sturman worked for Heuermann from 2017 to 2018 at his architectural office in Midtown.She said the irony is not lost on her that it was DNA from a discarded piece of pizza crust that prosecutors have used to tie Heuermann to the Gilgo Beach murders. He has plead not guilty to all the charges.Learn more about your ad choices. Visit podcastchoices.com/adchoices