Palmer, dubbed "The Prince of Poisoners," was responsible for as many as 11 murders, including his wife, four of his children, his brother and his mother-in-law.
Palmer loved women and betting on horses. He paid for his habit by taking out insurance on his victims shortly before they died.
Police became suspicious when Palmer tried to bribe a coroner investigating the death of his friend.
Palmer was convicted of poisoning the friend and was ordered to be hanged.
More than 30,000 spectators showed up for his execution in Stafford, England.
-- Scott McCabe