Corrected entry: Throughout the series of the Hannibal Lecter films, his name remains the same. He is a wanted man. He would have been arrested and questioned at the very least between the end of 'Hannibal Rising' and the beginning of 'Red Dragon'. This would probably have convicted him. The 1950's police may have had limited technology but they would have his name at least on record. Even if the 1950's police thought Hannibal had been killed in the explosion in 'Hannibal Rising', they would have to assume he was still alive when they couldn't find his body (or body parts for that matter). I guess its a bit like the London serial killer 'Jack the Ripper' who was killing his victims a lot earlier than Hannibal was. They had hardly any technology, no evidence and no idea who he was, but I'm sure that if someone was calling himself 'Jack the Ripper' 20-30 years later, he would be 'brought in for questioning.
Corrected entry: I may need correcting here, but if the 1950's police (especially the war crimes inspector) believe that Hannibal Lecter has committed murders, Hannibal must be a wanted man, with his name and photo on a wanted persons list? At the start of Red Dragon when Hannibal is captured, Hannibal still uses the name Dr Hannibal Lecter. Surely his name would have been known to the authorities and he would have been captured (and most likely found guilty) years before red dragon.
Corrected entry: Hannibal's final victim in the movie is supposed to be in Melville, Saskatchewan, and he is told it is near Saskatoon, Saskatchewan. These two cities are 356km apart, and about four hours drive away, longer in the 1950's. This is further distance apart than Paris to Marseilles, France, where most of the movie took place. Also, Melville is surrounded by farmland and fields, not the forest depicted in the movie. The Prairies near Melville are pretty much barren of trees.