Complex sentence: The concept of blood guilt was the basis for the laws called sippenhaft once used by Nazi Germany to arrest occasionally execute the families of political dissidents, namely those involved or connected to the July 20 plot to assassinate Adolf Hitler.
Split into simpler sentences: The concept of blood guilt was the basis for the laws called sippenhaft. The sippenhaft laws were once used by Nazi Germany to arrest occasionally execute the families of political dissidents, namely those involved or connected to the July 20 plot to assassinate Adolf Hitler.