Ominously Open Door

""Why is there never a surprise party behind these ominously open doors?""

- David Sinclair, Numb3rs, "Guilt Trip"

The good guys are having a hard time finding a lead for the current investigation. They find a possible culprit or a vital link in the investigation. The team gets an address and find the door slightly open.

Too bad whoever they find behind that door, be it a suspect, relative or complete stranger, can't help them close the case.

See also Your Door Was Open, Open Says Me; contrast Locked Door.

This is a Death Trope so don't be surprised by spoilers behind the ominously open folders.

Comic Books

 * In Arkham Asylum a Serious House On Serious Earth, the parts that focus on the backstory of the founder, Dr. Arkham, has a scene where he walks into his house after finding the door wide open, calling for his wife and daughter. Guess what he finds.

Film

 * In The Ninth Gate, when Johnny Depp goes to the rare book store to retrieve the titular book he hits the doorbell only to find the door ajar. The store owner, his friend Bennie is found.
 * In The Whole Nine Yards, when the detective knocks the door to find it open, he naturally takes out his gun.

Live Action TV

 * Numb3rs is the trope namer, as seen in the first quote.
 * Law and Order and all of its offspring live and breathe this trope.
 * Subverted in the episode . The cops find an ominously open motel door, one slowly opens it, dramatic music plays... and then the oblivious resident ambles up behind them with the bucket of ice he'd been getting.