Marisela Sandoval, 22, was shot to death by her long-term, on-again/off-again boyfriend, Miguel Angel Rangel, in front of their 6-year-old son on July 27, 1998, in Garden Grove. Police are still searching for Rangel, who is wanted for murder and possession of a controlled substance. “He was just a straight-up criminal,” Garden Grove PD Det. Michael Farley said. “He had a fairly significant rap sheet… and a history of violence, especially with regard to her. They used to fight a lot.” Rangel, now 42, is on both the Orange County District Attorney’s and the Garden Grove Police Department’s Most Wanted…