In the late 1980s and early ‘90s, a young respiratory therapist made medicine his whole life. But the extra shifts and multiple jobs started taking a toll — and it wasn’t long before rumors began circulating that Efren Saldivar’s “magic syringe” was putting patients in body bags.

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Even though he helped produce life-saving vaccines and water purification practices, Dr. Shiro Ishii’s biowarfare facilities and epidemics launched by his team are likely responsible for hundreds of thousands of deaths.

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Coming out of the influenza pandemic of 1918, Dr. Shiro Ishii wondered if disease could be used as a weapon. After invading Manchuria in the early 1930s, Japan authorized him to conduct horrific experiments on Chinese locals to determine the effectiveness of biological warfare.

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After getting away with two murders in 2008, Anthony Garcia tried returning to medicine — but repeated rejections left him spiraling. Once again, he focused his revenge on Creighton University doctors.

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Wanting to make his parents proud, Anthony Garcia tried to complete his residency to become a doctor. Four failed attempts at four different institutions later, Garcia knew a path in medicine wasn’t for him — so he set out on a quest to enact revenge.

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Hoping for a miracle cure, British heiresses Claire and Dora Williamson traveled to Linda Hazzard’s sanatorium in Washington in 1911. But when their childhood nurse becomes concerned for their welfare, it’s a race against time — and Hazzard — to free them.

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In the early 1900s, Dr. Linda Hazzard claimed that her special starvation regimens could cure any ailment. What her patients didn’t realize was that she wasn’t even a real doctor — and they were more likely to die under her care than recover.

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In June 2001, San Diego toxicologist Kristin Rossum was arrested on suspicion of murdering her husband, 26-year-old Greg de Villers. While her family defended her in the media, investigators discovered one piece of evidence that would clinch their case.

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When Greg de Villers died of an apparent suicide in 2000, his wife Kristin was distraught. But an investigation revealed he had been murdered with a lethal dose of fentanyl — and Kristin had the knowledge, the means, and the motive to do it.

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