Richard Castle: Looks like she was stabbed with a knife.
Kate Beckett: Mmm.
M.E. Sidney Perlmutter: To the untrained eye, perhaps. But... what you don't know about postmortem analysis could fill a book, Mr. Castle. In fact, it has. Numerous times.
Richard Castle: Fine. So, it was not a knife.
M.E. Sidney Perlmutter: Ah, wrong again. It was a knife, but "stabbed" implies the blade was thrust into the victim, uh, whereas this wound was produced by it being hurled into her chest.
Kate Beckett: What is this, "Last of the Mohicans"? What kind of knife is it?
M.E. Sidney Perlmutter: Uh, one with a hilt that matches these small bruises on either side of the wound. It killed her instantly, severing the left anterior descending artery.
Kate Beckett: Okay, so either that's the luckiest knife toss in the world...
Richard Castle: Or, she was killed by a circus knife-thrower. Like the Great Throwdini.