I don't think the looting, mass rapes and murders of the Red Army in Germany can be debated, there is enough evidence. It's just that the subject has not been touched by historians because it's a "dirty" one, who cares about the death of some "nazi germans" right? "They got what they deserved." Is a very popular opinion, and while that may be true, it is not right to conveniently forget about what happened.
By '44 STAVKA had a serious issue with POWs not reaching interrogation centers, they were killed (murdered) in the handling between the front line and interrogation.
There is one documented incident where a russian unit killed a workers battalion (men and women) from Ukraine, in late -44.
There's a book on this otherwise widely avoided subject by Niklas Sennerteg,
Stalins Hämnd (Stalin's Revenge). Don't know if there is a english translation available though.