21: Pedro Lopez The Dirty Stach Monster of the Andes.

Pedro Lopez and his dirty stach were responsible for the rape and murder of at least 110 girls between the ages of 8 and 12 but experts believe his body count could possibly be over 300. The real kick in the face is that he was released from prison and went into hiding.

Sources:
Biography of Pedro Alonso Lopez, Monster of the Andes (thoughtco.com)
Pedro Alonso Lopez - Crimes, Life & Facts - Biography
Serial Killers Documentaries Full |Pedro Alonso Lopez (Monster of the Andes) - Serial Killer Documen - Bing video
 "Why Did They Free Pedro López, the Monster of the Andes?". 
Pedro Lopez - Principle source articles (archive.org)
The weirdest and most bizarre crime stories of 2019 | Fox News
Music by Jonas Bjornastad
Cover Art by Charnell