There are few killers who kill for the fun of it.
2 seconds sound clip from the The Bat (1959) movie soundboard.
You can hear this line at 00:46:46.894 in the Blu-ray version of the movie.
Quote context
[...]
- There will be a crew here shortly from headquarters, dusting for fingerprints, taking photographs.
- But in the meantime, Mrs. Patterson, you aren't leaving the house tonight, are you?
- Don't, I'll talk to you in the morning. Goodnight.
- Dale called him at my request. She told me he was coming.
- Who else heard her tell you that?
- There are few killers who kill for the fun of it.
- Now, these young ladies are staying here tonight?
- Yes, they're my house guests.
- Well, when my crew arrives, we'll be busy for a while. So I'd suggest that...
- That we go to our rooms? That's a very good idea. Come on, girls.
[...]