In 1884 two sisters made their way to the gallows after taking four lives by administering arsenic and then claiming insurance payouts, with more recent research having discovered that they may well have been part of a syndicate that took many more lives.
A year after John's death, Margaret had married Thomas Higgins and by November 1882 young Mary had died, having been insured for £22. Within two months Margaret Jennings was dead and again insurance money was collected. On each occasion the sisters had waited until the victim was already ill before administering the fatal dose, making it easier to get a doctor to issue a death certificate.
After these three deaths the sisters moved, so as not to arouse any further suspicion, to 105 Latimer Street. No deaths occurred there and in September 1883 they moved to 27 Ascot Street, where Thomas Higgins was selected as the next victim. He was insured for nearly £100, but an attempt to take out a policy for an extra £50 failed when a drunken Thomas refused to undergo a medical examination, a fact he probably told to his brother Patrick.
After Thomas' death on 2nd October 1883, Patrick visited a number of insurance societies and found that the money had already been drawn. He approached the doctor, and they went to the coroner with their suspicions. The funeral was stopped so a post mortem could take place and Higgins was arrested. Flannagan fled the house but was taken into custody a few days later.
Both were charged on 16th October after arsenic was found in Thomas Higgins' corpse. The three other victims were exhumed and traces of arsenic found in each. After a three day trial, the sisters were found guilty in 40 minutes and sentenced to death. They were hanged at Kirkdale Gaol on 3rd March 1884.
In 2003 Angela Brabin published a book called The Black Widows of Liverpool, which carried out further investigation into the killings. She uncovered evidence that suggested many more may have met the same fate and that although Flannagan and Higgins may have administered the poison, many more stood to profit from their deeds.