The Death Cap Mushroom Murders

One unhinged person murders their in-laws and the sister of her mother-in-law via death cap mushrooms. 

Sources: 

1) https://www.bbc.com/news/articles/cwy3ngr2n3vo
2) https://en.wikipedia.org/wiki/Leongatha_mushroom_murders
3) https://www.abc.net.au/news/2023-11-02/police-charge-erin-patterson-mushroom-poisoning-deaths/103056694
4) https://www.theguardian.com/australia-news/2025/apr/30/erin-patterson-mushroom-poisonings-murder-trial-ntwnfb
5) https://www.skynews.com.au/australia-news/son-pays-tribute-to-extremely-thoughtful-and-generous-parents-gail-and-don-patterson-after-they-died-from-mushroom-poisoning-following-leongatha-lunch/news-story/2b5f5ad4e303390e5312c4077b7b46a9
6) https://www.sgst.com.au/news/memorial-service-brings-home-depth-of-korumburra-tragedy
7) https://www.bbc.com/news/world-australia-67002918
8) https://en.wikipedia.org/wiki/Amanita_phalloides
9) https://www.abc.net.au/news/2023-10-04/mushroom-poisoning-victim-heather-wilkinson-memorial-service/102929526
10) https://www.abc.net.au/news/2025-07-10/gail-don-patterson-heather-ian-wilkinson-erin-patterson-mushroom/105513208