When did Hitler start sending Jews to concentration camps?

According to Ian Kershaw's biography the earliest hard evidence of Hitler's hatred of the Jews dates from 1916 in World War 1, when Hitler was 27.

___

According to the movie "Hitler: The rise of evil" it was during WWI.

_____

There are two schools of thought on when Hitler became obsessively antisemitc. The first believes that it began early in his life and was firmly in place by age 18. The second, more recent, school of thought is that Hitler got on quite well with Jews in Vienna and that he only became a fanatical antisemite during Word War 1. See Ian Kershaw's biography, Vol. 1 ("Hubris") for details.

Many of the 'theories' about Hitler's hatred of the Jews, especially those claiming to be based on a single experience early in his life, are just fanciful guesswork.

The reasons given by Hitler in his autobiography, 'Mein Kampf', are not trustworthy. The book is Propaganda, and a long rant by a man with a huge chip on his shoulder.