The boyfriend of a Portland woman whose body was found in a river is being charged with her murder. Portland police arrested 27-year-old Joel Olavarria-Rivera outside a hospital in Westbrook. He had reported to police that his girlfriend, 21-year-old Jennifer Soto, was missing. Her body was found in a river Saturday morning. Olavarria-Rivera and Soto had two children together. Police believe Soto was killed in her Portland apartment.