Quotes / Absence of Evidence

Gregory: Is there any other point to which you would wish to draw my attention?
Holmes: To the curious incident of the dog in the night-time.
Gregory: The dog did nothing in the night-time.
Holmes: That was the curious incident.

"What tipped me off was the lack of evidence."
Batman, Justice League

Faith: So you think there's some big conspiracy?
Buffy: (looks in filing cabinet to find all the files are empty) You were saying?
Faith: So those papers are gone. That doesn't prove anything.
Buffy: Except that someone didn't want us to prove anything.
Buffy the Vampire Slayer, "Consequences"