This method of 'proof' would get you a reprimand from a junior high school math or science teacher.
So all you have to do is go with the idea that there is evidence that Joe Jackson 'might' have been touring military installations in the Mid-Atlantic at a particular time, then locate military photos from that period and area, then find someone who resembles Jackson....and it becomes Jackson...because no one can prove that Jackson was in a different location at the time that photo was taken?
Besides failing the very general test of 'Does it even look like Jackson?', failing the more specific test of facial characteristics;e.g-chin and ear fail, you are also failing to deliver any evidence that he WAS there; instead, asking for proof that he was not?!?