Although Forsythe was not a newcomer to film when he was cast by Hitchcock—he’d been in a half dozen films already—there was a freshness he brought to the role that was perfectly suited to the material. As I wrote in Writing with Hitchcock, Sam Marlow is “perhaps the most grounded character in Hitchcock’s work” and for this reason, I feel Forsythe was the better choice than Cary Grant, who had been considered for the role early on by the director.
The Trouble with Harry was very closely adapted from the novel of the same name by Jack Trevor Story, yet Hitchcock and screenwriter John Michael Hayes created one very significant scene which finds no parallel in the source material. In this scene, a millionaire art collector bestows a set of wishes upon Sam as payment for his paintings, and Sam shares the wishes with his newly made friends. Forsythe’s affable quality helps make this one of Hitchcock’s warmest films.
Forsythe would be directed by Hitchcock twice more following The Trouble with Harry, once on television for an episode of The Alfred Hitchcock Hour titled I Saw the Whole Thing, and in the director’s 1969 feature release, Topaz. Forsythe’s casting, against type, as the judge accused and ultimately guilty of rape in …And Justice for All was another big screen highlight.