Sentenced to life without parole.[322] Amy Archer-Gilligan United States 1910 to 1917 5 48+ A nursing home proprietor believed to have poisoned as many as 60 patients from her homes and her second husband. Charged with five murders originally, this was lowered to just one following her admission of guilt, and was found guilty of second degree murder. Died in a mental hospital in 1962.[323] Michael Swango United States Zimbabwe 1981 to 1997 4 35–60+ Medical Doctor who killed patients.[324] Kermit Gosnell United States 1989? to 2011 4 100+ Gosnell, who ran an abortion clinic, was charged with eight and convicted of four murders.