Criminal law and procedure

Das Legalitätsprinzip looks like the English principle of legality and names something else. In English that phrase means nobody may be punished for conduct that no law forbade at the time; German calls that das Gesetzlichkeitsprinzip. Das Legalitätsprinzip is a duty laid on the prosecution. Once there is ein Anfangsverdacht, it must investigate, and once the suspicion has hardened into hinreichender Tatverdacht, it must bring charges, whether or not it thinks the case worth the trouble. Its counterpart is das Opportunitätsprinzip, which lets the authorities drop minor matters. A learner who reads the first term as a guarantee for the accused has turned an obligation of the state into a right of the citizen, and will misread every sentence in which a prosecutor explains why an investigation could not simply be left alone.