@Walter Hinteler,
The USA isn't the only country in the world. Other countries have different political systems, different court systems, different legal systems, different ...
A German prosecutor has formal responsibility for investigation, and the police are considered to be a subordinate helping agency.
We have a single national criminal code, a single national code of criminal procedure, and a unified court system.
A prosecutor is not an elected official, but a civil servant operating within a hierarchical system, appointed for life like all civil servants of the "Beamten category".