Constables in the United States
While Constables primarily serve the Courts, they belong to the executive branch of government.
Judiciary of Greece
According to the Constitution, there are three categories of courts: civil courts, penal courts and administrative courts. The supreme court of the civil and penal justice is the Court of Cassation, while the supreme court of the administrative justice is the Council of State. Hence, Greek judges belong to one of these two branches. Consequently, an administrative judge is not entitled to judge a penal or civil case, while a civil judge is entitled to judge a civil or penal case but not an administrative one.