A member of ACAT-Germany for over 35 years, Gabriela M Sierck has been involved in the organisation of ACAT-Germany's annual events and contacts with church institutions concerned with the protection of human rights as well as with other human rights institutions in Germany. She is also a member of the board of ACAT-Germany.

Her commitment has always been based on her indignation at the violation of human rights and the scandal of torture.  She is particularly interested in scientific research into the causes of torture and other human rights crimes. Another concern is the independence of the judiciary and the strengthening of international criminal law.

A lawyer, criminologist and mediator by training, she spent 10 years working in the field of human rights and 30 years as a civil servant in the German parliamentary administration (mainly in the field of European law).

Her wish for the future: that all states accede to the Rome Statute of the International Criminal Court and actively support it in the prosecution of aggressive war and war crimes.

In June 2024, she was elected to the FIACAT International Board for a four-year term.