Now look, you can't be sure of killing a man by throwing him off a train that's going 15 miles an hour. The only way you can be sure is to kill him first and then throw his body on the tracks.
12 seconds sound clip from the Double Indemnity movie soundboard.
You can hear this line at 01:19:08 in the DVD version of the movie.
Quote context
[...]
- Walter, I'm a very great man.
- This Dietrichson business, it's murder and murders don't come any neater.
- Go ahead. I'm listening. (2)
- You know what? That guy Dietrichson was never on the train.
- Two possibilities, and I personally buy the second.
- You're way ahead of me, Keyes.
- Well, look, it was like this. They killed the guy, the wife and a somebody else...
- And the somebody else took the crutches and went on the train as Dietrichson...
[...]