Dr. Bux has participated in many international human rights investigations for the International Forensic Program at PHR. His work for international courts includes the exhumation of mass graves in the former Yugoslavia for the United Nations International War Crimes Tribunal, and providing written reports for the Special Prosecutor for the International War Crimes Court in Sierra Leone. The Archdiocese of Guatemala appointed Dr. Bux as Forensic Medical Expert for exhumation of Archbishop Juan Jose Gerardi in 1998.
In 2001 he exhumed and identified 14 guerillas of the Tupac Amaru who were responsible for the takeover of the Japanese Embassy in Lima, Peru, in the late 1990s. As a consultant for the Attorney General of the Republic of Mexico he exhumed the body of Guillermo Velez Mendoza and gave a declaration under oath in 2002. Dr.Bux returned to Mexico in 2005 as a consultant for the Attorney General of the Republic of Mexico to examine and review case files, examine skeletal remains, and offer suggestions for future work in the case of disappeared women in the border towns of Ciudad Juarez and Chihuahua.