This is from the novel Approaching Nick of Time. Kaname sort of ends up being possessed by the essence of a dead girl who was a test subject in the experiment that went wrong and led to the creation of the whispered. The resulting girl, whoever she is (she's sort of Kaname, but sort of the other girl, if that makes any sense) believes she shot Sousuke and Tessa dead, and oddly enough Tessa and Sousuke both have visions of her killing them, but find themselves still alive when they come to. The novel is actually a pretty good read, but it definitely moves the series into some kind of weird territory.