SS-Sturmbannführer Richard Baer, the last camp commandant, died in detention while still under investigation as part of the trials.
Defendants ranged from members of the SS to kapos, privileged prisoners responsible for low-level control of camp internees, and included some of those responsible for the process of "selection," or determination of who should be sent to the gas chambers directly from the "ramp" upon disembarking the trains that brought them from across Europe ("selection" generally entailed inclusion of all children held to be ineligible for work, generally under the age of 14, and any mothers unwilling to part with their "selected" children).
In the course of the trial, approximately 360 witnesses were called, including around 210 survivors.
Proceedings began in the "Bürgerhaus Gallus", in Frankfurt am Main, which was converted into a courthouse for that purpose, and remained there until their conclusion.

State Attorney General (Hessian Generalstaatsanwalt) Fritz Bauer, himself briefly interned in 1933 at the Heuberg concentration camp, led the prosecution.
Bauer was concerned with pursuing individual defendants serving at Auschwitz-Birkenau; only 22 SS members were charged of an estimated 6,000 to 8,000 thought to have been involved in the administration and operation of the camp.
The men on trial in Frankfurt were tried only for murders and other crimes that they committed on their own initiative at Auschwitz and were not tried for genocidal actions perpetrated "when following orders", considered by the courts to be the lesser crime of accomplice to murder.

At a 1963 trial, KGB assassin Bohdan Stashynsky, who had committed several murders in the Federal Republic in the 1950s, was found by a German court not legally guilty of murder.
Instead, Stashynsky was found to be only an accomplice to murder as the courts ruled that the responsibility for his murders rested only with his superiors in the KGB who had given him his orders.

The legal implication of the Stashynsky case were that the courts had ruled that in a totalitarian system only executive decision-makers could be convicted of murder and that anyone who followed orders and killed someone could be convicted only of being accomplices to murder.
The term executive decision-maker was so defined by the courts to apply only to the highest levels of the Reich leadership during the National Socialist period, and that all who just followed orders when killing were just accomplices to murder.
Someone could be only convicted of murder if it was shown that they had killed someone on their own initiative, and thus all of the accused of murder at the Auschwitz trial were tried only for murders that they had done on their own initiative.

Thus, Bauer could only indict for murder those who killed when not following orders, and those who had killed while following orders could be indicted as accomplices to murder.
Moreover, because of the legal distinction between murderers and accomplices to murder, this meant that an SS man who killed thousands while operating the gas chambers at Auschwitz could only be found guilty of being accomplice to murder because he had been following orders, while an SS man who had beaten one inmate to death on his own initiative could be convicted of murder because he had not been following orders.

Bauer is said to have been opposed in the former purpose by the young Helmut Kohl, then a junior member of the Christian Democratic Union.
In furtherance of that purpose Bauer sought and received support from the Institute for Contemporary History in Munich.
The following historians from the Institute served as expert witnesses for the prosecution; Helmut Krausnick, Hans-Adolf Jacobsen, Hans Buchheim, and Martin Broszat.
Subsequently, the information the four historians gathered for the prosecution served as the basis for their 1968 book, Anatomy of the SS State, the first thorough survey of the SS based on SS records.

Information about the actions of those accused and their whereabouts had been in the possession of West German authorities since
SS-Sturmbannführer Richard Baer, the last camp commandant, died in detention while still under investigation as part of the trials. Defendants ranged from members of the SS to kapos, privileged prisoners responsible for low-level control of camp internees, and included some of those responsible for the process of "selection," or determination of who should be sent to the gas chambers directly from the "ramp" upon disembarking the trains that brought them from across Europe ("selection" generally entailed inclusion of all children held to be ineligible for work, generally under the age of 14, and any mothers unwilling to part with their "selected" children). In the course of the trial, approximately 360 witnesses were called, including around 210 survivors. Proceedings began in the "Bürgerhaus Gallus", in Frankfurt am Main, which was converted into a courthouse for that purpose, and remained there until their conclusion.
State Attorney General (Hessian Generalstaatsanwalt) Fritz Bauer, himself briefly interned in 1933 at the Heuberg concentration camp, led the prosecution. Bauer was concerned with pursuing individual defendants serving at Auschwitz-Birkenau; only 22 SS members were charged of an estimated 6,000 to 8,000 thought to have been involved in the administration and operation of the camp. The men on trial in Frankfurt were tried only for murders and other crimes that they committed on their own initiative at Auschwitz and were not tried for genocidal actions perpetrated "when following orders", considered by the courts to be the lesser crime of accomplice to murder.
At a 1963 trial, KGB assassin Bohdan Stashynsky, who had committed several murders in the Federal Republic in the 1950s, was found by a German court not legally guilty of murder. Instead, Stashynsky was found to be only an accomplice to murder as the courts ruled that the responsibility for his murders rested only with his superiors in the KGB who had given him his orders.
The legal implication of the Stashynsky case were that the courts had ruled that in a totalitarian system only executive decision-makers could be convicted of murder and that anyone who followed orders and killed someone could be convicted only of being accomplices to murder. The term executive decision-maker was so defined by the courts to apply only to the highest levels of the Reich leadership during the National Socialist period, and that all who just followed orders when killing were just accomplices to murder. Someone could be only convicted of murder if it was shown that they had killed someone on their own initiative, and thus all of the accused of murder at the Auschwitz trial were tried only for murders that they had done on their own initiative.
Thus, Bauer could only indict for murder those who killed when not following orders, and those who had killed while following orders could be indicted as accomplices to murder. Moreover, because of the legal distinction between murderers and accomplices to murder, this meant that an SS man who killed thousands while operating the gas chambers at Auschwitz could only be found guilty of being accomplice to murder because he had been following orders, while an SS man who had beaten one inmate to death on his own initiative could be convicted of murder because he had not been following orders.
Bauer is said to have been opposed in the former purpose by the young Helmut Kohl, then a junior member of the Christian Democratic Union. In furtherance of that purpose Bauer sought and received support from the Institute for Contemporary History in Munich. The following historians from the Institute served as expert witnesses for the prosecution; Helmut Krausnick, Hans-Adolf Jacobsen, Hans Buchheim, and Martin Broszat. Subsequently, the information the four historians gathered for the prosecution served as the basis for their 1968 book, Anatomy of the SS State, the first thorough survey of the SS based on SS records.
Information about the actions of those accused and their whereabouts had been in the possession of West German authorities since
Frankfurt Auschwitz trials