The U.S. state that has produced the greatest number of serial killers is New York with 137 separate serial killing cases. Falling in second is California with 128, then Florida with 112, Texas with 97 and rounding out the top five, Washington with 95.
As a whole, the U.S. produces the greatest number of serial killers in the world. The U.S. has produced 76 percent of all of the world's serial killers. The Pacific Northwest has long had a reputation for producing serial killers. The most prolific serial killer in the United States, Gary Ridgway, committed 49 serial murders in the greater Seattle area as the Green River killer.