The medical room used for “treating” prisoners at Stuttho, the Nazis’ first concentration camp outside of Germany.

At snowy Stutthof concentration camp near Gdansk, Poland, we huddle in a stark, damp-cold room with low ceilings, a long wooden examining table and large black & white image of syringes. We learn from our guide that medical treatments were conducted here, but ones usually not for saving lives — for taking them.

We discuss that the administering of lethal doses of phenol or Zyklon B didn’t start and end with the Nazis. Their genocidal actions to perpetuate the Aryan race were greatly influenced by America’s eugenics movement — the science of human improvement through controlled breeding. “It’s a parallel Americans don’t like to make because it’s too disturbing,” Dr. Halperin says. (For a related story, click here.)

Few know that from 1907 to 1977, our own country forcibly sterilized some 68,000 people in a medicalized effort to eliminate breeding of the mentally and physically disabled, the poor as well as the “immoral” (i.e., violent criminals and sexual deviants). The U.S. also enacted racial segregation and restrictions on mixed-race marriage and immigration to further such social engineering.

Three decades after America enacted its eugenics measures (that by this point were being discredited by modern science), the Third Reich began sterilizing people in 1933. Initially the Nazis aimed to eradicate “defective” Germans, which included even those with drinking problems or vision/hearing disorders. Two years later came Germany’s Nuremberg Laws of racial hygiene, and in 1939, its T4 euthanasia program.

One of the best-known Auschwitz inmates to be executed with a phenol injection was St. Maximilian Kolbe, a Catholic priest who volunteered to undergo two weeks of starvation and dehydration in the place of another inmate.

These Nazi actions of racial cleansing would be precursors to their full-scale genocide of 11 million people, including 6 million Jews, whom they deemed “parasitic vermin” in need of total annihilation. From 1933 to 1939 (the first phase of euthanasia killings), as many as 425,000 people would be sterilized, and after the T-4 program, 70,273 would die by lethal injection and poison gas. After the second phase that occurred during World War II, the total number of deaths would reach more than 325,000 (including massive killings in concentration camps).

The Germans were grateful to America’s Rockefeller Foundation for having helped them develop and fund eugenics programs on par with the Carnegie Institution Department of Genetics in Cold Spring Harbor, N. Y. One of the programs that evolved from this exchange of ideas included Josef Mengele, later infamous for his barbaric research at Auschwitz. Another figure influenced by the collaboration included Hitler’s personal physician, Karl Brandt, “the father of lethal injection.” He was the first to use and advocate cyanide injections to the heart to kill “defective” children, and later, others.

“Euthanasia reached beyond Germany when, under cover of war, many of the medical personnel in charge of killing patients there were shipped east to Poland to oversee the death camps’ mass gassing of people that began in 1942,” Dr. Halperin says.

After capital punishment was re-legalized in America on July 2, 1976, lethal injections would gain favor six years later as being a more “humane” way of execution; the condemned death row inmate would lose consciousness before he or she died from a poisonous chemical cocktail administered intravenously. Thirty-three states now carry out the death penalty, primarily through lethal injection. (Though European pharmaceutical companies, in countries without the death penalty, are making the necessary drugs more difficult for the U.S. to obtain.)

An empty canister of Zyklon B, the cyanide-based poison used in the Nazis’ gas chambers.

As for the gas chamber, only Mississippi and Arizona continue its use, though only for prisoners convicted before lethal injection was instituted in each state. During such executions, hydrogen cyanide pellets similar to Zyklon B emit a poisonous gas, and, if all goes as planned (which, like lethal injections, sometimes don’t), within 18 to 25 minutes the person being gassed meets the same violent physical end as those killed in gas chambers during the Holocaust.

The death penalty maintains strong support in America; the end justifies the means, advocates say. Abolitionists concur it amounts to cruel and unusual punishment and that innocent people have died. Either way, “it’s important to put the use of lethal injection and the gas chamber into historical perspective,” Dr. Halperin says.

With both killing mechanisms in our face at every turn, that’s not difficult for us to do.