We gave the Japanese amnesty for https://en.wikipedia.org/wiki/Unit_731 in exchange for their biological warfare data. We had the option to do the right thing (burn it, put it on display), but we validated it.
I'm not sure complete amnesty was the best thing to do, but I don't think destroying the data would be the best either. If we had burned the data that was already gathered, it would have been a complete waste of human life. Those people experimented on were murdered, and burning the data would have made those murders pointless. By using that data, we could prevent human death in the future.
The problem was, this was done scientifically. Controls, and all that. The problem was they were intentionally treating their subjects (Jewish) like lab rats.
But when WWII ended, we realized some of their data could be used for the space race. And the US used it.
The ethical issues here are all encompassing. Do you get rid of it and let them die in vain? Do you use it, and benefit on people executed over genocide conditions? There's no good way to answer this, as the converse has a valid argument as well.
I look back and say, well, I was born in the early 80's. It's about 60 years before my time (would have to be born in the 20's to serve in the 40's).