- How long have you been standing there?
- Long enough.

4 seconds sound clip from the Double Indemnity movie soundboard.

You can hear this line at 01:43:58 in the DVD version of the movie.

Quote context

[...]

- The janitor did.

- Seems you leaked a little blood on the way in here.

- Yeah. Wouldn't be surprised.

- I wanted to straighten you out on that Dietrichson case.

- So I gather.

- How long have you been standing there?

- Long enough.

- Kind of a crazy story with a crazy twist to it. One you didn't quite figure out.

- You can't figure them all.

- That's right. I guess you can't at that.

- Now I suppose I get the big speech, the one with all the two-dollar words in it. Let's have it.

- Walter, you're all washed up.

[...]