His name, was Oskar Dirlewanger, he served as a Machine Gunner in WWI in the Western Front, invading Belgium and later fighting in France, he ended the war on the Eastern Front with many medals and as a Lieutenant, his experiences appear to have lead to his taste for violence and sick sexual perversions and he became an alcoholic.
To skip through much of the rest of his biography he was a violent right wing street thug after this, he later joined the Nazi Party, later on he was sentenced to prison for sexually abusing a 14 year old girl, he was expelled from the Nazi Party and was even at one point sent to a concentration camp, but due to connections he still had within the SS by this point, not only was he released but he was allowed to become part of the SS Reserve and later fought as part of the Condor Legion in Spain, due to this he was reinstated into the Nazis just prior to WWII and became a member of the Waffen SS and was given his own command in what would become the 36th Waffen SS Division.
The beginnings of this division were, relatively speaking and from a military point of view, easy enough to understand, they initially took men convicted of poaching to in theory, help tackle Partisans in the woods of conquered territories, however as the war progressed it became a free for all for who got into this specific division, the mentally deranged, violent criminals, rapists, the mission became a more general "policing" of certain stretches of occupied territory, one such case being Belarus.
Their propensity for violence, rape and pillaging was too much even for the SS, many other SS commanders made complaints about this divisions behavior if you can believe that, and wanted them taken off the field as also their randomly violent behavior was sometimes a risk to their own men, but these fell upon deaf hears due to Oskars connections.
It is said that one of the favorite pass times of this division was rolling into a village, putting as many villagers as they could into a barn, setting it alight and machine gunning down anyone that tried to run out, the tales of indiscriminate violence and rape (also of children) from this time are numerous but it was during the Warsaw Uprising when the division truly gained notoriety and cemented them as quite possibly the sickest and most violent of all the SS's many atrocities.
During the Warsaw Uprising, Himmler gave Dirlewanger free reign to loot, pillage and rape the city back into submission, to give you just a taste of some of the shocking things he did, I quote the following:
https://en.wikipedia.org/wiki/36th_Waffen_Grenadier_Division_of_the_SS
https://en.wikipedia.org/wiki/Oskar_Dirlewanger
These are just a taste, Dirlewanger finally met his end after being shot in the chest by Soviet Soldiers, survived and went into hiding while fighting in Eastern Germany, he was then captured and as the legend goes, allegedly beaten to death by Polish Soldiers in French Service in his Cell, but his official death certificate states he died of "natural causes".
Personally I hope they made him severely suffer before he died, under his personal orders (and by his own hand at times), thousands upon thousands of women and children were raped and consequently hundreds of thousands more would be murdered, brutally and indiscriminately, I think it is a testament to how brutal these guys were that even many in the SS themselves, hated this man and what he was doing (super ironic as well).
Anyway that is a small taste of what I think was one of the more chilling tales of German atrocities during WWII, there are other resources if you want to learn more but actually they are somewhat limited and some will require translation, particularly from Polish.
