Gerardo Ríos Mairena

Gerardo Ríos Mairena, also known as 'Guaco', is a convicted felon who gained infamy for his role in the horrific massacre of five university students in Liberia, Costa Rica, in January 2017. With a history of drug-related offenses, Ríos Mairena was linked to the crime through forensic evidence and was subsequently sentenced to 216 years in prison for multiple counts of homicide and sexual abuse.