Smart, a 19-year-old college student, disappeared in 1996.
A California jury has found Paul Flores guilty in the murder of 19-year-old college student Kristin Smart in 1996.
His sentencing is scheduled for Dec. 9. He faces 25 years to life in prison.
His father, Ruben Flores, was found not guilty of accessory to murder in connection with the crime.
Paul Flores, a former classmate of Smart, was charged with murder, while his father was charged with being an accessory to the crime. Prosecutors say he helped hide Smart's body on his property in Arroyo Grande before moving it in 2020.
Smart went missing walking home from a party at California Polytechnic State University, San Luis Obispo. Her body has never been found, but authorities arrested Paul and Ruben Flores in April 2021 and found alleged evidence related to Smart's murder in their homes.
Paul and Ruben Flores were tried at the same time, but with separate juries hearing the case together. A verdict was reached in Ruben Flores' case on Monday; that decision was sealed until Paul Flores' jury reached its verdict Tuesday and they could be announced simultaneously.
San Luis Obispo County Sheriff Ian Parkinson told reporters that the Kristin Smart case "is not over."
"This case will not be over until Kristin is returned home," he said during a press conference Tuesday with the family. "That I remain committed to."
Smart's body was never found after she disappeared in 1996.
Kristin Smart's father, Stan Smart, made a statement on behalf of the family in the wake of the guilty verdict.
"Without Kristin, there is no joy or happiness with this verdict," he told reporters during a press conference with the San Luis Obispo County's district attorney's office and sheriff's office Tuesday.
He called the journey to the trials a "long, overwhelming and emotional" one, and spoke directly to his daughter.
"To our Kirstin, almost three decades ago our lives were irreparably changed on the night you disappeared," he said. "Know that your spirit lives on in each and every one of us."
"Not a single day goes by that you aren't missed, remembered, loved and celebrated," he continued.
Kristin Smart's mother, brother and sister were also present at the press conference.
Ruben Flores said he was "relieved" about his not-guilty verdict as he left the courthouse Tuesday.
"There was a lot of made-up things," Ruben Flores told reporters. "You look through it and there is no evidence against anybody, me or Paul."
When asked if he had any comments for Kristin Smart's family, he said, "I feel bad for them because they didn't get no answers about what happened to their daughter, and we don't know what happened to their daughter."
Ruben Flores' attorney, Harold Mesick, said his client never should have been charged and that the verdict was the "just outcome."
He said "there is a reasonable inference to be drawn" that Smart might still be alive, and that prosecutors never proved her death.
Commenting on the split verdict, Ruben Flores said the jurors who found his son guilty "were carried away with feelings about the family."
Kristin Smart's family will join a press conference on the verdicts with the San Luis Obispo County's district attorney's office and sheriff's office that's scheduled for 7 p.m. Tuesday, ABC News has learned.
