I think the idea is that Agent 47 is so good, he’s the best option. It doesn’t matter if some locals might remember a bald white man walking around town. It’s not enough to accuse him of the crime, and he’s never going to get caught anyways.
That being said: Agent 47 is European (Romanian). Even though David Bateson is South African, it’s not like Agent 47 is some random American Tourist who draws attention to himself. He’s a well-dressed European business man named Tobias Rieper. He was there for a meeting and the ICA definitely has the ability to fabricate an alibi if any police make the connection (or even remember that he was there).
At the end of Freedom Fighters it was stated that all of his assassinations were either Unsolved or reported as Accidents. The problem that we really face is that we don’t know the “Canon” assassinations. We can assume it’s always Silent Assassin with no direct witnesses and no hard evidence, but because each game allows so much freedom, one has to keep in mind that according to the world of the game, Agent 47 never makes mistakes or gets caught trespassing.