A prosecutor says he won`t bring charges against Saline County Sheriff Phil Mask over testimony the sheriff gave in a juvenile sex case. Mask testified for the defense during the trial of former Shannon Hills Police Chief John Brown. The ex-chief was convicted of sexual assault of a 15-year-old and was sentenced to 25 years in prison. During trial, Mask testified that he doubted Brown`s guilt, though his deputies investigated the case and made the arrest. Mask said he questioned the girl`s truthfulness because of the way she smiled at him when she and her family came to the sheriff`s office for an interview. Benton County Prosecutor Bob Balfe was named as special prosecutor to probe whether Mask was to be charged after Saline County Prosecutor Robert Herzfeld asked for an investigation. Balfe said police and prosecutors built a solid case but Mask committed no crime by testifying about his doubts.