Overall, there were very few prosecutions of Kapos, whether Jewish or gentile. One problem was that many of these individuals did not survive the war or its immediate aftermath. These individuals could easily end up as victims in the highly mercurial nature of camp life. Those that did survive sometimes ended up the victims of extrajudicial justice within the camps after liberation. For those that did survive, their dual status as oppressors/oppressed made prosecutions rare and difficult.

Israel did conduct a series of trials of between 38 prosecutions of Jewish Kapos between 1951-1964. However, details on these trials are very sketchy as the Israeli courts have sealed their records for 70 years. Even though the Israeli law these individuals were prosecuted under, the Nazi and Nazi Collaborators Punishment Law (1950), could have resulted in a death sentence, the sentences for the 15 defendants convicted was relatively mild. Else Tarnek, a female Kapo and block commander at Auschwitz-Birkenau, received a two year sentence in 1951 but since it had been two years since her arrest, she was released the same day. The Israeli judge said of Tarnek:

We must take the circumstances under consideration: the defendant was placed in charge, against her will, of a block of 1000 persecuted women lived. She herself was a persecuted person, just as they were.

The judges in the Kapo trials tried to parse out mens rea (mental state) of the defendants and try to determine if the situation they found themselves in the camp was the compelling rationale for their behavior. The Kapos and other Jewish "helpers" such as ghetto policemen did not lend themselves well to standard legal prosecutions because they themselves were often victims of the regime that gave them a small amount of power to abuse.

Sources

Bazyler, Michael J., and Frank M. Tuerkheimer. Forgotten Trials of the Holocaust. New York: NYU Press, 2014.

Wolf, René. "Judgement in the Grey Zone: the Third Auschwitz (Kapo) Trial in Frankfurt 1968." Journal of Genocide Research 9, no. 4 (2007): 617-635.