This has come up a number of number of times in the past, with the most conclusive and informative answers being here and here.

The problem with this question, and perhaps why it hasn't garned the kind of walls-of-text we favor around here, is that the question of whether or not Hitler killed anyone personally is trivial in the most basic sense of the word. He orchestrated two violent coups, one of which was successful, which led to widescale political crackdowns, racial and sexual oppression, the largest war in the history of humanity, and one of, if not the, most appalling genocides in that same history. He may not have pulled a trigger, but he certainly pulled the levers. The question of whether he ever killed anyone is moot in light of those facts, and will forever be a footnote in history.