Alibi for a witch

From classsiccrimefiction.com: "If Lester Ballard had had any say in the matter, he wouldn't have been seen dead in the cheap gabardine suit, the green cotton shirt, the pointed brown suede shoes. But as he was in fact dead, he had no control over such sartorial lapses. Ruth Seabright, governess to Lester's son Nicky, found his murdered body and was as baffled by its incongruous attire as by the fact of murder itself. But that is only the first of many puzzles. Where, for instance, is Nicky? Who has been searching Ruth's bedroom? How can a corpse be in two places at once? Set beneath the dazzling azure skies and brilliant sun of a small seaside resort in Southern Italy, this exciting crime story is as baffling as it is entertaining."