Davis police Sgt. Scott Smith said property recovered in Walker's vehicle and in the beach area indicates he took his own life.
Walker's family reported him missing at 1 a.m. Monday. Walker left home around 2:45 p.m. Sunday to go to his office on the UC Davis campus, police said. Surveillance photos show Walker leaving his office, but he was not seen or heard from after that.
Jeremy Stinson, supervising ranger with California State Parks, said two people walking on South Salmon Creek Beach found Walker's body in the surf around 5:30 p.m.
Walker was a professor of clinical diagnostic bacteriology at UC Davis. His research was related to infectious avian, bovine, equine, ruminant and swine diseases.
He was an expert in bacteriology and veterinary pathogens important to agriculture, and his international areas of interest included Europe and the Far East, according to the UC Davis Web site.