Carl "Coral" Eugene Watts is considered the most prolific serial killer in the United States. He confessed to killing 12 women but it is believed that he is responsible for the death of 100 women. He killed women in Texas, Michigan and Canada and they ranged in age from 14-44. He was able evade police with his savvy and street smarts.
References:
Evil Eyes by Corey Mitchell
https://texaspolicenews.com/default.aspx?act=NewsLetter.aspx&category=News+1-2&newsletterid=34265&menugroup=Home
https://abc13.com/coral-eugene-watts-serial-killer-killed-nine-women-timely/5456125/
https://www.nytimes.com/2007/09/22/us/22watts.html
https://www.dallasobserver.com/news/evil-eyes-6388157
https://kfmx.com/sunday-morning-slasher-the-serial-killer-texas-almost-set-free/
https://murdervictims.com/case/coral-watts-serial-killer/