Reconstruct the Following as a Standard-Form Syllogism; Then, Determine Whether

Essay

Reconstruct the following as a standard-form syllogism; then, determine whether it is valid using either a Venn diagram or the rules of the syllogism.
"Not necessarily, Mr. Dalgliesh. Suppose it's a double bluff. Suppose he's saying in effect, 'Look, I can prove I knew the Whistler was dead. Whoever killed Hilary Robarts didn't know. So why aren't you looking for someone who hadn't been told that the Whistler's body had been found?'" -P.
D.James, Devices and Desires