Is there a difference in these two sentences?
Are these two sentence equivalent in their meaning, or is there subtle differences because of where the word who is placed?
No one has come forward who remembers seeing Bill that Monday.
No one who has come forward remembers seeing Bill that Monday.
Yes - the first states that no witnesses have come forward. The second implies that, though some people have come forward, they don't include anyone with the required information.
In the first sentence people may have come forward: in the second they have.