Hmmm. I never read anything that said Hitler had accepted Jesus. His actions in life definitely did not point to that.
I once heard an analogy that likened both heaven and hell to a banquet table. God has provided us with this banquet table; it has no head, it goes on forever in two directions. Seated on either side of the table are all the people who have ever lived and died. Those who have accepted God's forgiveness partake of the heavenly feast of everlasting life with gusto. Those who have not just sit there with unbending arms. They can see the food, touch the food, smell the food, but can never put it to their lips to partake of it because they have never accepted God's grace. God did His part to provide the feast, but the sinners have not done theirs to partake of it. All they need to do is bend!
Yeah, I think Hitler is there, too, but I doubt he is eating of the food of eternal life.