Throughout the course of the film, there are many well-plotted clues to A Haunting in Venice's killer's identity. In true whodunit fashion, these well-laid clues are also one of the movie's most satisfying elements, as they allow viewers to piece together the mystery alongside Hercule Poirot, Kenneth Branagh's mustachioed, top-notch detective. The third installment in Branagh's series of Poirot adaptations, A Haunting in Venice deviates from Agatha Christie's Hallowe'en Party. Set in eerie, post-World War II Venice, the film revolves around the tragic death of Alicia Drake (Rowan Robinson), a young woman who supposedly drowned in the canals.

https://screenrant.com/haunting-in-venice-who-is-killer-identity-clues/