Last night, Barbara Walters sat down with Mariah Carey and interviewed her. At one point the conversation turned to American Idol, and Mariah Carey confirmed what she had said previously. Namely, that Nicki Minaj threatened to kill Mariah and that Mariah took it so seriously that she upped her security and was fearful for her children's lives. She also said Nicki should keep the show classy.
Source:
http://www.crazydaysandnights.net/2013/01/mariah-carey-confirms-that-nicki-minaj.html