Actually, there are so many variations to the question of serial.killings.
The US state that has produced the greatest amount of serial killers is New York with 137 separate serial killing cases......2nd is California with 128, & 3rd is Florida with 112.......don't know where I read Ohio at? Maybe because quite a few serial killers have been coming out of Cleveland past few years.
The US is the country with the most documented serial killers with 2,625......
