My family went to Washington DC and we went to the United States Holocaust Memorial Museum. At first it was the Jews, but eventually they tried to make, I think it was a white race, blue eyes, blonde hair. They would measure facial structure to determine lineage. They tried to get rid of the weak also. One part said that they went into the mental hospital, and there was a story about an 8 year old boy that they executed and an 8 year old girl that they executed. I know the Hitler wasn't blonde.
Check out the web site for United States Holocaust Memorial Museum
It has some good information.
It took us 3 hours to get through this museum, so if you want to know more, hopefully you could go to this museum. I know they had these gas chambers that looked like people were going into take a shower, this room had fake shower heads. WHen the room was full, they would throw down these pellets that would release gas. It didn't take very long, before it went from jews to pretty much everyone but Germans.