Her motives are clear. First, his death allows her to bad mouth the US, yet again. But, she knew that he would have to tell about his knowledge of her collaboration with the Muslim terrorists, before AND after her kidnapping. And, there is the money. He actually paid the Muslim kidnappers about half the cash he was authorized to offer. Once she killed him, she got to keep the balance.
No, once the investigation is over, it will become clear that she murdered the brave Italian agent and profited mightily from it. We don't, however, wish her to leave the middle-east because she is the one who has been providing the Mossad, IDF and CIA with such useful targeting information. The terrorists did not find this out or they would not have released her alive, no matter how high the ransom.
How do you figure all this? We said we fired on the car.