In order to properly investigate a crime, we must first (obviously) properly define it. The Holocaust (Shoah) was a premeditated, carefully planned and executed mass murder of millions of Jews (by blood, not by religious affiliation – so it was a genocide, not a religious massacre) by the Nazis (i.e., individuals and organizations of Nazi Germany), their puppet regimes (i.e., in Croatia) collaborators (i.e. in Latvia, Lithuania, etc.) and allies (i.e. in Romania) in 1939-45 (mostly n 1941-45)
With the ultimate objective of physically exterminating all Jews in Europe. All estimated eleven million Jewish people – from Lisbon to Vladivostok; from Norway to Sicily.
The victims of this genocide (killed not for what they did or for what they believed in) but for who they were by blood (i.e. by birth) include all Jews who perished during this murderous persecution – regardless of the cause of death.
In other words, not only those who were shot by members of Einsatzgruppen (or other murderers) or poisoned to death by carbon monoxide (or Zyklon-B) in stationary gas chambers in Auschwitz, Chelmno, Majdanek, Treblinka or Sobibor, but also those who died in ghettos or in campy of starvation or diseases (i.e., typhoid), those who died in transit (en route to ghettos, labor camps, death camps, etc.), those who were literally worked to death (exterminated through labor) in concentration camps, etc., etc. All of them are murder victims – for all practical (and legal) purposes.