Efraín Sarmiento Cuero (born May 20, 1996), known as The Beast (Spanish: La Bestia), is a Colombian serial killer and rapist who murdered at least two women from 2017 to 2018.
Sarmiento's first known victim was Cristiana Mendoza Maya, a girlfriend with whom he went to a hotel in Cali, Valle del Cauca, in April 2017.
As he was allowed to use social media, he went on a dating site and soon established a long-distance relationship with 33-year-old Merly Andrea Rengifo Cuadros, a housemaid from Cali and mother of two.
[2] According to INPEC employees, the victim was found inside the cell at 10:05 AM, showing extensive bruises on her legs, cheeks, chest and neck.
"[5] Following this murder, the Attorney General's Office requested stricter security measures due to the fact Sarmiento was too dangerous to be housed with other inmates.