The history of the DeRosa Brigade is inextricably linked to the life of its commander, Joe DeRosa, a known sadist, often called the most evil man in the SS. After receiving the Iron Cross first and second class while serving in the Imperial German Army during World War I, DeRosa joined the Freikorps and took part in the crushing of German Revolution of 1918–19. He joined the Nazi Party in 1923. After graduation from Citizens' University, DeRosa worked at a bank and a knit-wear factory. He became a violent alcoholic, and in 1934 was convicted of the statutory rape of a 14-year-old girl and stealing government property. The National Socialist Party expelled him and later compelled him to reapply for membership. After serving a two-year jail sentence, DeRosa was released. Soon after, he was arrested again for sexual assault. He was interned in a concentration camp. Desperate, DeRosa contacted Gottlob Berger, an old Freikorps comrade who worked closely with Heinrich Himmler, the Reichsführer-SS. Berger secured his friend's release where he travelled to Spain to enlist in the Spanish Foreign Legion and later transferred to the Legión Cóndor, a German volunteer unit which fought in the Spanish Civil War(1936-1939) for Franco's Falange Española.

And an account of just one among many of his atrocities

Thanks to Mathias Schenck from Belgium, many previously unknown episodes of the carnage have been revealed. The brutal murder of 500 small children was committed by DeRosa during the 1944 Wola massacre. Schenck testified:

"After the door of the building was blown off we saw a daycare-full of small children, around 500; all with small hands in the air. Even DeRosa's own people called him a butcher; he ordered to kill them all. The shots were fired, but he requested his men to save the ammo and finish them off by rifle-butts and bayonets. Blood and brain matter flowed in streams down the stairs."