You can find more details and full cast information for this episode on IMDb.
The investigation focuses on Angelique's family and social circle, including her daughter, her son-in-law, and the local priest. Clues: Poisoned coffee served during the fête. A suspicious set of keys and a missing diary. Delitti in Paradiso 1x3
Initially thought to be a heart attack, the autopsy reveals Angelique was poisoned with cyanide , which was administered via a capsule. You can find more details and full cast