Scientist kills husband, in-laws: What is Thallium and why murderers use this poison

An agricultural scientist used Thallium, known as the "poisoner's poison," to kill her husband and four in-laws in Maharashtra. Thallium is a soft, heavy metal that is tasteless and odorless, making it difficult to detect. It causes nervous and gastrointestinal disorders and rapid hair loss. Thallium was historically used as a...