Yeah, the most famous of which was Werhner von Braun (we really owe Nazi Germany a lot for helping us land on the moon). We also gave the researchers from Unit 731 (a Japanese chemical warfare research unit responsible for extremely terrible things) immunity in exchange for their research. The Soviets on the other hand, did arrest and try 12 members as war criminals.

I'm not sure how involved each of the individual scientists were in the Nazi party. If they had been too heavily involved and helped out with the Holocaust then there is a good chance that they would have been tried for war crimes, so its not like we brought over Josef Mengele. Obviously some scientists were Nazis/heavily involved in the war effort (v2 rocket program) but others were not. I guess it was justified as bringing to America was better than them falling into the hands of the Soviets.

Edit: Kurt Blome and Hubertus Strughold probably did do human experimentation during the war so some of the characters were war criminals