Holocaust callout

Hey /politics/, roughly a little over a week ago, I got into a trainwreck of a debate on /n/ regarding the holocaust, and that one archive- containing millions of documents totaling to 16 miles long- was brought up. Which had information on all the various victims of the holocaust. Then, someone brought up an email conversation they had with one of the archivists, asking if there were forensic documents indicating if any of the victims were killed by zyklon-b, which the archivists replied with no.

They still haven't replied to me asking the same thing, but it dawned on me: why the fuck would the germans have autopsies of the people they killed?

I'm posting this because the same guy asked me to post it here, and /n/ is just too much of a shithole, so....

I just have one thing to reply to at the moment:

"I did not say "autopsies" (though it may very well be included -- you do know that they had a health care system, hospitals, doctors etc.? And they did have several documented autopsies that I know of, but don't ask me to source them, it would be really hard from where I'm standed), I asked, like you said, about forensic documents indicating any victim of gassings. Which, in plain English, means if they established, with any sort of proof, a gassing victim. They unsurprisingly haven't."

I meant basically the same thing. Exactly why would Germany hold forensic documents on the people they killed?