#4 – Pedro Rodrigues Filho
Filho, just like Gary Ridgeway, was a prolific serial murderer. He confessed that he murdered more than 70 women throughout the 1970s.
He committed his first murder at the age of 14. While he was in prison, he even killed his own father who was also serving a sentence for murdering several people. After spending more than three decades in prison, Filho was released in 2007. However, he was once again incarcerated in 2011.