He didn't like the looks of things, so he changed the lock on the door.
5 seconds sound clip from the After the Thin Man (1936) movie soundboard.
You can hear this line at 01:38:35 in the DVD version of the movie.
Quote context
[...]
- Now listen, if you made her dicker with the cops, ok.
- But that ladder stuff is a lot of malarkey. No one did come down that ladder.
- And Landis wasn't killed in her place.
- The only reason he wasn't killed in her place was that Anderson was found out.
- Pedro came in here yesterday to lay a new rug.
- He didn't like the looks of things, so he changed the lock on the door.
- When Anderson came in, he found that he was locked out.
- Then he heard Pedro telephone me downstairs...
- So what?
[...]