Per local German coverage on reported crime statistics, many crimes go unreported, and a number of crimes that would be included in US crime statistics are exempted from German reporting.

Also, now that Germany has...diversity...the crime rate went up pretty significantly.

So I would say, all in all, that homogenous populations are the greatest deterrence, followed by the magnitude of punishment being significantly more important at a societal level, though the risk of getting caught dominates the thought process for regulatory/low-punishment crimes.