As in, did people also help handicapped people into hiding? How did the nazi authorities distinguish who they murdered and who could "pass"? Also, considering the large numbers of handicapped people that were murdered in Germany, how did the post-war handicapped care restart?
To add a bit to /u/UWCG 's answer:
It is important to know that the already mentioned Law for the Prevention of Hereditary Diseased Offspring cast a very wide net in terms of who was to be its victim. It was part of the Nazi push to eliminate those from the gene pool who according to their eugenic and racial theories were a problem for the German racial body and therefore should not procreate. This included people whom we today would also recognize as handicapped and mentally-ill and some we wouldn't: The main victims of the law were persons born with a learning disability (in Nazi terms "Schwachsinn", which is commonly translated as "feeble-minded"); Schizophrenics; people with what we today call bi-polar disorder; hereditary epilepsy; Chorea Huntington; hereditary blindness; hereditary deafness; and alcoholism.
It's really important here to emphasize that while the Nazis might have called these diseases hereditary, they had a very limited understanding, comparatively, to how both these diseases and genetics worked – in some cases even so far, that they cared little for actual medical evidence of these diseases being indeed hereditary or advancing their knowledge of these diseases and potential treatment. Both the decision to introduce this law as well as the Health Boards that made the decisions on who was to be sterilized were politically, not medically driven. Very, very often, it was not medical status or indication that lead to sterilization but rather social strata: Most of the 400.000 victims of the Nazi sterilization program (during which 5000-600 women and 600 men died of complications from the operations) were not from families with money but rather from the lower classes of society. It wasn't just that they were handicapped; it's also that they were poor and handicapped. Another seldom mentioned group of victims of this also were the children of German women and black French soldiers conceived during the Rhineland occupation after WWI.
A certain pattern of this fashion also continued with the T4 killing program. Instituted in 1939 and run by Philipp Bouhler of the chancery of the Führer, the program targeted handicapped and mentally ill patients of various institutions and asylums in Germany to be killed in six centralized killing facilities (Hartheim, Sonnenstein, Brandenburg, Bernburg, Hadamar, Grafeneck). This too is a crucial point: The T4 killing program was intended to murder those who were in the care of institutions. As you can see from the linked propaganda below, the arguments were always that these people cost society too much for their care and so forth. Partly because of this logic and partly because of propaganda and public relations images, the Nazis did not kick down the doors of families with handicapped children to take them away and murder them, they murdered those who were in care in state- or privately-run institutions. This perpetuated the pattern mentioned above, meaning that families who could afford to care for their handicapped or mentally ill members at home faced comparatively little danger of having their relative killed.
With the T4 program underway in 1940 and 1941, more and more information leaked out due to a sometimes shockingly bad conduct by the bureaucracy of the program (some families receiving ashes twice e.g.) as well as because it was hard to hide six facilites with crematoria burning a lot of human bodies from the general public. Public opposition to the program began to form, strongly driven by the churches, especially the Catholics, and public protests began. Hitler was booed on stage on one occasion and the Nazi leadership realized that the centralized program could not be sustained in the face of the public turning against it. Which is why it was stopped in 1941.
However, a decentralized killing program continued in secret that mainly targeted children. By October 1941 when the program was officially "stopped" 70,000 people had been killed. From 1941 to 1945, a total of 200,000 people were killed, the vast majority of them children. What set this decentralized program apart from the T4 program before it was that now it was the T4 organization under Bouhler anymore who decided who was to kill and who was to stay alive based on their catalogue of criteria similar to those mentioned above with sterilization – now, it was solely up to the treating doctors, nurses, and other hospital and institution personnel to decided who was killed and who stayed alive. Basically every health care professional treating those with handicaps or mental illness now held the literal power of life and death. And they did use to a great extent as the numbers above show.
As for the post war situation:
Here, historians face the same challenges as in the case of other, lesser researched victim groups, namely that few of the victims came forward to tell their story and were subjected to continued discrimination and stigmatization after the war. Here even with the additional problem of the handicapped victims of the Nazi regime being for the greater part dead at the end of the war, having been subjected to the medical killing program.
While there are survivors of certain Nazi medical institutions, the commonly available literature makes no specific mention of survivors of the centralized medical killing program (stopped in 1941) with myself also believing that there really were none. Additionally, this problem is increased by mentally handicapped and children, which were the main victims of Nazi institutionalization after the centralized medical killing program had been stopped in 1941 leaving little trace in the historical record from their own perspective.
One of the major cases, which I'll use here to illustrate the situation and is somewhat representative for the post-war situation in Germany comes from Austria: Friedrich Zawrel was born in 1929 into a very poor Viennese family with an alcoholic father. Having displayed what the Nazis termed "asocial" behavior as a child and with a mother unable to feed him and his siblings, he was institutionalized in Vienna's Am Spiegelgrund hospital, a place where the Nazis killed about 800 children in the course of decentralized medical killing and conducted sadistic experiments on said children. Zawrel's main tormentor was a physician named Heinrich Gross, who was the main personal responsible for the sadistically experiments and the killing at Am Spiegelgrund.
Zawrel survived the war but without a school or professional degree and scared by his experience as a teen, he was unable to hold down a steady job and started to resort to petty criminal acts. In 1972, he and others broke into a supermarket to steal money and food for which he was arrested in 1974. After spending a year in detention awaiting trial, he was forced to see Austria's most prominent court psychiatrist at the time in order to determine if he was mentally fit to stand trial: Heinrich Gross, his former tormentor from Am Spiegelgrund.
Gross had evaded persecution after the war and had risen to prominence with the Austrian medical-judicial system, doling out psychiatric evaluation of patients along the lines of Nazi medical criteria. And so he did with Zawrel: He recommended incarceration in a mental facility for recidivists due to his "asocial character". A sentence, which meant life-long incarceration due to the fact that inmates of these facilities had to be declared cured or not a danger to society anymore; something which almost never happened and which Gross knew how to prevent in Zawrel's case.
It took until 1981 and an extensive media campaign to get Zawrel released and another 19 years to start a trial against Gross; a trial that in the end amounted in nothing due to Gross advanced dementia in 2000.
Friedrich Zawrel is one example of a survivor who suffered in very real terms under the consequences of having been a victim of Nazi Germany and being victimized again by his former tormentors who managed to build a good life for themselves. There are probably thousands if not hundred thousands similar examples out there less well known than Zawrels.
Sources:
Burleigh, Michael (1995). Death and Deliverance: 'Euthanasia' in Germany 1900–1945.
Friedlander, Henry (1995). The Origins of Nazi Genocide: From Euthanasia to the Final Solution.
Klee, Ernst (1983). Euthanasie im NS-Staat. Die Vernichtung lebensunwerten Lebens.
Bock, Gisela (1984). Zwangssterilisation im Nationalsozialismus. Studien zur Rassenpolitik und Geschlechterpolitik.
Their experiences were certainly similar. On July 14 1933, the Nazis passed the "Law for the Prevention of Hereditarily Diseased Offspring." The law allowed for the forced sterilization of anyone determined to need it by a Hereditary Health Board intended to forward the Nazi's goal of 'racial hygiene' and their race policy.
This was accompanied as well by dehumanizing propaganda about the disabled: the picture there is basically saying that the same 5.50 reich marks could feed and house a single disabled man, or it could feed and house a family of five. The disabled were labeled as a burden on society and "unworthy of life." This would also relate to what would be known after the war as Aktion T4, the involuntary euthanasia program. Doctors selected by the Reich were allowed to "euthanize" people after examining them. Children were not exempt:
Fortunately, there were good people such as Otto Weidt, who did try to help out by hiring and sheltering disabled workers. Claus Von Stauffenberg, who had a role in a nearly-successful assassination attempt was also disabled, but as he had become disabled due to battle wounds, he was above suspicion. War veterans who were disabled were generally exempted from disdain as they were viewed as having sacrificed for the country; according to that article, they were often given safe, comfortable jobs.
Per William Shirer's The Rise and Fall of the Third Reich, another person in the room inadvertently kicked the briefcase containing the bomb to the far side of a beam: if not for that, Hitler likely would have been obliterated that day. Instead, he was only rattled and banged up.
Ultimately, approximately 200,000 disabled people were murdered between 1940-45. As for the postwar treatment of the disabled in Germany, I do not know much.
