Constables in the United States
While Constables primarily serve the Courts, they belong to the executive branch of government.
Separation of powers
Besides the constitutional court the judicial branch at the federal level is made up of five supreme courts—one for civil and criminal cases ("Bundesgerichtshof"), and one each for administrative, tax, labour, and social security issues. There are also state ("Länder / Bundesländer") based courts beneath them, and a rarely used senate of the supreme courts.