How did the persecution of the Jews people turn into genocide?

Jews were systematically oppressed long before the Holocaust. At first, they were isolated from the other Germans and dehumanized (forced to wear the Star of David to signify they were Jewish); from there they were segregated. They were then encouraged to leave Germany and other countries under German rule as they started to expand (their home land). Then, they were forced into ghettos. Finally, they were transported into death camps and concentration camps.

They were killed for who they were that is genocide periosteum