Jane Toppan
Jane confessed to thirty-one murders in 1901, but is believed
to be responsible for at least twice that many. She is quoted
as saying that her ambition was to have killed more helpless
people than any other man or woman who ever lived.
http://www.mayhem.net/Crime/serial1.html
http://www.websurfer13.com/Absinthejane_toppan.htm