Nearly three decades after Kristin Smart vanished, investigators served a search warrant at the home of her killer’s mother, as the search continues for the late Cal Poly student’s remains. Investigators with the San Luis Obispo County Sheriff’s Office returned Wednesday to the Arroyo Grande property on East Branch Street to serve a search warrant three years after a group of scientists say they discovered a detection of potential remains. The home belongs to Susan Flores, the mother of Paul Flores, who was convicted in 2022 of killing Smart in 1996 when they were both students at Cal Poly San Luis Obispo. He was sentenced to 25 years to life in prison in 2023, where he has been attacked twice. Smart was legally declared dead in 2002, but her body has never been found, despite previous searches of multiple family properties. Susan Flores has never been charged in connection with Smart’s murder.…