Georgia Southern University Police continue to investigate the case of John David Keeton, a 19-year-old student who has been missing since March 28. University Police Chief Michael Russell released a flier Tuesday morning that has been distributed around campus.Keeton is believed to have traveled to the San Francisco area, according to the flier, and has expressed suicidal tendencies. The flier describes Keeton as a white male, 6 feet 1 inch, 165 pounds, with brown hair and brown eyes.