What were the events that led to kristallnacht

Kristallnacht happened for many reasons. Before the 'night of the broken glass' many events happened that snowballed into this huge night of destruction. Firstly, "Herscchel Grynszpan, a German Jew who was living in France [was] outraged by the Nazi's treatment of his family." he "walked into the German Embassy in Paris and shot Ernst vom Rath, the secretary." This supposedly "spawned a night of terror." Weeks earlier before Kristallnacht, hundreds of thousands of  Polish Jews living in Germany were shipped back to Poland in boxcars after being arrested. Before this, many Jews had not believed the tales of horror, but this event made things suddenly become much more real.  (The evidence in quotations is cited from the book Parallel journeys)