???

It's a reasonably well known saying. Hence the 'proverb' tag (although it isn't literally a proverb).

http://en.wiktionary.org/wiki/murder_will_out

OK, but then it doesn't correspond at all to the german translation. Where does the discrepancy lie ?

The saying "Murder will out" isn't literally about murder so much as general wrongdoing. It means that "the truth (about evil deeds) will be uncovered."

I don't speak German, but it doesn't seem that far out.

I'm not saying it's far out, but it hardly translates.
If we are to consider that "not seeming that far out" is satidsfactory, I might as well spare me the effort altogether.

In the case of proverbs and sayings there are several ways to 'translate' them.

1. You can translate them literally. Usually not a good idea as a literal translation of a saying can be completely incomprehensible.

2. You can provide an 'explanatory' translation. i.e. translate based on the meaning of the saying.

3. You can provide a proverb or saying in the target language that has a meaning "not that far out" from the original. This has the advantage that both examples are "proverbial".

thank you for the enlightenment, like I never translated a proverb in my life, yeah...