The Most Prolific Female Serial Killer in UK HistoryMary Ann Cotton was known as the black widow.Sam H ArnoldFeb 05, 2021∙ Paid11Share\the ledgeand, Public domain, via Wikimedia CommonsFor more than a century, Mary Ann Cotton was the most prolific serial killer in UK history, until Harold Shipman surpassed her victim count in 2000.…This post is for paid subscribersSubscribeAlready a paid subscriber? Sign inPreviousNext