Hitler was viewed as a hero in the beginning. He was a very good speaker and made promises of change in a country that was desperate for a better life. It was a gradual take over of the country. He convinced the people that he could make changes that would benefit them. He started the brown shirts which was much like a civilian enforcement group. Hitler convinced the people that part of the financial problems they faced were due to the Jews. Over time he made villains out of the gypsies, and anyone who spoke against him or his ideals. He turned children against parents by having the child report what he perceived as traitorous actions to authorities. By the time Hitler and his henchmen began to round up the Jews and others to be sent to concentration camps to be murdered, he had the country under his thumb and most were afraid to speak out for fear that they and their families would be killed as well. True, most civilians did not know, and did not want to know, what was really happening once their neighbors were loaded onto the cattle cars of death. It was not until the war was well under way that other nations found out the dirty secret that was so well hidden. By the time rescue came, millions had been killed. When one our you. S. Serviceman (I believe it was Patton, but am not positive) saw the horror of the survivors of the camps, he had photos made and took first hand testimony. He was of the belief that in some future generation there would be denial that the Holocaust ever occurred. It's horror would be too terrible to be believed. And, today, there are some who say it did not happen. But to humanities shame, it did.
Ever heard of the geneva convention(came about becasue of this). Hitler did not adhere to the rightful treatment of prisoners.he/nazi's commited mass murder in concentration camps like sobibor.treblinka,auschwitz.which are also known as extermination camps/death camps.in other words they took in millions of jews(polish jews/german jews,gypsies) under the guise of prisoner of war and then they executed them in many ways gas chambers disguised as showers,mass graves disguised as work sites,experimentation,starvation.
Actually, there were 42 attempts (and still counting) to kill Hitler. Watch the documentary.