Cesar Castillo Vallejo, 38, faces 20 years to life in prison when sentenced June 17 by Judge Ana Espana.
Castillo pleaded guilty to murder, hit-and-run and violation of a restraining order on the day his preliminary hearing was to go forward.
Authorities said Castillo repeatedly ran over 37-year-old Leonor Castillo with his 1998 Chevrolet Silverado in the 1100 block of Elm Avenue about 7 p.m. last Nov. 28. She died at the scene.
Deputy District Attorney Christy Bowles said the ex-spouses had met up earlier that day to go shopping. Afterward, he struck her with his white pickup truck once,"then drove down the street, made a U-turn, repositioned his truck and came back and ran over the victim a second time, killing her," Bowles said.
Castillo was on probation at the time for violating a protective order filed by the victim. He had also threatened her boyfriend, according to Bowles.
Vallejo, a maintenance man who worked in the Mission Bay area, fled to Mexico following the victim's death. He initially tried to take his children, ages 10, 8 and 3 with him, but the victim's mother persuaded him to leave them behind.
He surrendered at the San Ysidro Port of Entry on Dec. 1.
The couple's 12-year marriage ended over a year before her murder. Bowles said the defendant was hoping to reconcile with the victim, but became jealous and angry.