 He transferred to be public prosecutor in Munich in 1981, and because Deputy Head of the Criminal Law section of the German Federal Ministry of Justice from 1983 to 1986.He was then transferred back to be a full Judge in Weilheim, where he served for a further three years.Brüner then became Deputy Head of the Criminal Law Department of the Public Prosecutor's office in Munich, and in 1991 was Senior Public Prosecutor at the Office of the General Prosecutor in Berlin.