Born in Waltenhofen as the son of a dairy worker, Martin was able to take his Abitur thanks to a teacher, despite his father's opposition.
He subsequently went on to study law and economics at the Ludwig Maximilian University of Munich.
In 1946, Martin was appointed a judge in Sonthofen, and in 1950, he was employed in the Federal Ministry of Justice.
[2] As the IGFM's president of the board of trustees, the Chilean government of Augusto Pinochet considered him a "reliable friend".
In 1987, Martin together with board member Lothar Bossle, warned the Chilean authorities that the relations between West Germany and Chile might deteriorate if the crimes in Colonia Dignidad became known.