Looks like Linda Gotti is set to testify at the trial. She's Pete Gotti's daughter.

"John Gotti niece Linda set to testify in Bartolomeo Vernace trial"

"Federal prosecutors plan to call Gotti as a witness against reputed capo Vernace, who is charged in the 1981 murders of two men in a Queens bar."

http://www.nydailynews.com/new-york/john-gotti-niece-linda-set-rat-2-slays-article-1.1284320