Complex sentence: Hugh Ross Williamson, "Historical Whodunits" (1955) J.P. Kenyon, while raising some difficulties with the theory, agreed that of all the suspects Pembroke had by far the strongest motive for killing Godfrey.
Split into simpler sentences: Hugh Ross Williamson, "Historical Whodunits" (1955). John Philips Kenyon, while raising some difficulties with the theory, agreed that of all the suspects Pembroke had by far the strongest motive for killing Godfrey.