Prof. Dr. Müller studied law at the Universities of Erlangen, Munich and Geneva and was research assistant at Universität des Saarlandes. He qualified in 1976 and is a specialist lawyer for Criminal Law.

Having practised for more than 30 years, Prof. Dr. Müller is experienced in all areas of criminal law. He particularly acts in business crime cases ("White Collar Crime") and advises companies pre-emptively, i.e. in compliance questions.

From 1994 to 2006, he was a Board Member of the Munich Bar Association, being their Vice President from 1998 to 2006. He is a Member of the Criminal Law Committee of the German Bar Association.

He regularly lectures at the University of Passau. Moreover, he has been committed to professional training for lawyers and judges for many years.

Prof. Dr. Müller speaks German and English.