Alexander Elfgen studied law at the Heinrich-Heine-University in Düsseldorf and at the University of Cologne, specialising in international criminal law and criminal procedure law. He passed his final state examination at the Higher Regional Court of Cologne in 2022.

Alexander Elfgen has been a PhD Candidate and Research Assistant at the Institute for International Peace and Security Law at the University of Cologne since January 2023. In his thesis he is dealing with different questions regarding the prosecution of the crime of aggression under the German Völkerstrafgesetzbuch.

In addition, Mr Elfgen is very interested in the fundamental differences between national and international criminal law, in general constitutional law, in international humanitarian law in connection with its sanctioning under international criminal law and in general German criminal law.

In 2022, Mr Elfgen worked as a Research Assistant in the field of criminal tax law at a law firm in Bonn.

He is a member of the Cologne Center for Advanced Studies in International History and Law.