YOU SAID:

I wonder how long it'll take us to figure out who committed the crime.

INTO JAPANESE

犯人を突き止めるのにどれくらい時間がかかるのかしら

BACK INTO ENGLISH

I wonder how long it will take us to find out who did this.

INTO JAPANESE

犯人を見つけるのにどれくらい時間がかかるのだろう。

BACK INTO ENGLISH

How long will it take to find the killer?

INTO JAPANESE

犯人を見つけるのにどれくらいかかりますか？

BACK INTO ENGLISH

How long will it take to find the killer?