He never did anything like this before. How do we know...
4 seconds sound clip from the After the Thin Man (1936) movie soundboard.
You can hear this line at 00:16:08 in the DVD version of the movie.
Quote context
[...]
- Why are you looking so down in the mouth? You got family troubles, too?
- For heaven's sake, do you want the servants to hear you?
- I don't care. I'm going crazy. I can't stand it any longer. I'm going to call the police!
- You'll do nothing of the sort! Haven't we paid out enough to hush up his other scandals?
- He never did anything like this before. How do we know...
- Quiet!
- Beg pardon, madame, but shall I remove Mr. Robert's place?
[...]