Yeah, sure...if the shawl was at the scene of the crime, which nobody can demonstrate. And if chain of custody was maintained, which nobody can demonstrate. And if it hasn't been handled by anyone since the murder, when it's been handled by hundreds of people.
But I'm sure a disorganized paranoid schizophrenic wrote the "From Hell" letter and included part of Eddowes' kidney with it.
Oh, wait...it's an article in The Sun. That all but proves Kominski's innocence.