The Ventura County Star says the 22-year-old Oxnard man didn't want to support a child, and girlfriend Justina Cornejo told him she would not get an abortion.
A prosecutor says Olmos then hired two men to stage a robbery.
While Olmos and Cornejo were parked in a car at a Newbury Park overlook in January 2008, the men attacked the woman, punching her in the face and stomach.
The woman later gave birth to a boy who is now a healthy 2-year-old.