. >> i'm sharyn alfonsi. >> i'm jon wertheim. >> i'm scott pelley. those stories and more, tonight, on "60 minutes." ( ticking ) >> scott pelley: much of the world was horrified when saudi arabia sent a hit squad to turkey to murder "washington post" columnist jamal khashoggi. tonight, the man you are about to meet says a second saudi assassination team was sent to kill him in canada. saad aljabri was number two in saudi intelligence, and he was among the best friends america had against terrorism. now, saad is asking america's help. truth is hard to triangulate among spies, despots, and the middle east. you're going to hear that saad aljabri may not be spotless. but as a spymaster, saad says he has one more favor for america: a warning about a prince, with the power to trouble the world. >> dr. saad aljabri: i am here to sound the alarm about a psychopath, killer, in the middle east, with infinite resources, who poses threat to his people, to the americans, and to the planet. >> pelley: saad aljabri is talking about mohammed bin salman, who seized p