Pro boxer Felix Verdejo -- who competed in the 2012 Olympics -- has been hit with multiple criminal charges connected to the killing of a 27-year-old pregnant woman and her unborn child.
Verdejo surrendered to authorities in Puerto Rico on Sunday evening -- roughly 24 hours after the body of Keishla Rodriguez was found in a lagoon.
Officials say her body was in such bad shape, they needed to use her dental records to verify her identity.
The allegations into her killing are extremely disturbing ...
Officials say the FBI has been working with a witness who claims to have "firsthand, personal knowledge” of the incident -- because the boxer had "requested his help to terminate the pregnancy.