In Chapter three titled “Cyanides (HCN, KCN, NaCN)” of The Poisoner’s Handbook by Deborah Blum, Fremont Jackson and Annie were found dead in their bathroom at the, The Hotel Margaret, police immediately guessed that it could have been a double suicide though investigators didn’t find anything that could have been used to kill themselves. A medical examiner later did an autopsy and found out that cyanide could have been the cause of there death. Cyanide is an element, which is in groups, hydrogen cyanide made up of hydrogen, carbon, and nitrogen atoms, potassium cyanide is a white poisonous salt, and sodium cyanide which can also be the white poisonous salt. This element is related to Mr. and Mrs. Jackson death because cyanide poisoned them