We present the results of an empirical analysis on whether the anti-corruption agencies that were introduced to Singapore and Hong Kong and became a global trend through the UN and EU were helpful in suppressing corruption. We also discuss what the most effective criminal justice system should be. First, we present findings that show that there is no statistically significant difference of corruption levels between countries that introduced anti-corruption agencies and those that did not. On the other hand, we found that the direct investigation by the prosecution, the independence of the prosecution service, and the freedom of the press helps lower corruption in the public services sector. Based on the above results, we draw policy implications for an effective criminal justice system to curb corruption.