3. Gary Leon Ridgway (50 to 71 victims)
Gary Leon Ridgway or the Green River Killer is known as one of the most prolific serial killers in the American history, who was found guilty for murdering nearly fifty women, but Ridgway later confessed to killing 71. He was arrested in the city of Renton and investigators confirmed his crime through DNA samples and paintings he made. Ridgway has a humble-looking individual who kept a deep hatred toward women. During interviews by psychologists, it was revealed that Ridgway was mistreated by his mother and this could be the earliest trigger for his aberrant sexual behavior.