[A pause. He doesn't move, his eyes on Mrs. O'Leary for a moment as those words echo through his head.

'I know one of our murderers.]

...really? [He sounds a touch skeptical because he always does, but there's definite intrigue in his tone.] You're sure? How? [And then, because of some things he himself has experienced:] If it's gonna incriminate somebody you don't have to tell me who told you if the information came from somewhere else.