Martin was the second oldest of six brothers and a sister - Heinrich, Johannes, Wilhelm, Helene, Max (died in infancy), Walter, Bernhard.
In this capacity he was active in organizing protests and demonstrations in opposition to the impending seizure of power by the National Socialist German Workers Party, as well as preparing for undercover work for the KPD.
In East German law records, there are two cases in the year 1933 concerning crimes in the concentration camp Schloss Osterstein in Zwickau, in which Hoop is mentioned.
On 2 May 1933 (cf also Gleichschaltung), Hoop was arrested in the café restaurant of the department store "Tietz" in Chemnitz and transported to Schloss Osterstein in Zwickau, which at the time served as concentration camp.
In the trial proceedings, details of mistreatment of prisoners are reported in depth, including the following testimony that refers to the death of Martin Hoop during the night of 10–11 May 1933.
5 and as neighbors we were well acquainted… After the so-called seizure of power in 1933 by the National Socialist German Workers Party, it was rumored that comrade Hoop had been eliminated.
We thereupon discontinued our inquiry, while at the same time the violent death of comrade Hoop became an open secret…"In the contemporary history of the German communist party (KPD) in Saxony, the Bautzen City Councillor Martin Hoop was known as an ardent supporter of the Weimar Republic presidential candidate Ernst Thälmann.
[10] It was, for example, only the Bautzen district leadership who was opposed to the expulsion from the Party of Ruth Fischer and Arkadi Maslow, two of Thälmanns political predecessors, Hoop was one of the few KPD functionaries opposed to the theory of “relative stabilization” and of its implications in the Weimar Republic (see also, 1925 German presidential election), called for a return to agreements made at the 10 July 1925 KPD congress (only weeks before the intervention of the Communist International),[11] and brought attention to the failure of united front politics in Saxony.
[12] In autumn of 1923 an extensive weapons cache was discovered in the Bautzen machine factory Münckner & Co., where Hoop had once been employed.
On the same occasion, Martin Hoop also spoke about the May Day workers’ demonstration, characterizing the treatment by the Bautzen police as 'disgraceful and brutal'.
On 5 September Rädel spoke on the subject of the Dawes Plan and “How Are Reparations To Be Paid.” "… during the open discussion, two persons participated: a Social Democrat, Arndt, who was shouted down and therefore not heard, and the communist Hoop…Upon a suggestion made by Hoop at the end of the meeting, a resolution was endorsed for the release of the communist comrade Pchalek, who was alleged to have formed terror groups, and who was still in custody…"Among other activities during his service as Bautzen City Councilman, Hoop led a demonstration against the Tscheka trial taking place in Leipzig in early 1925.
[16][17] Weakness in the east Saxon KPD leadership made possible more effective control of local party affairs through national parliamentary representatives like Siegfried Rädel, who, together with the left majority, supported the politics of Ernst Thälmann.
[1] At the end of World War II, the trade union of coal miners “Morgenstern” resumed its activities as a state-owned enterprise which operated until 1977 under the name Martin Hoop Pits.