The body of Berkeley activist Carlos A. Davila, who worked with senior citizens trying to obtain health care, has been found at the foot of a Marin County cliff, shot once in the head. Davila’s family and co-workers were told of the identification as they gathered for a fund-raiser to raise money to search for Davila. The 42-year-old man had been missing since May 18. Officials said the partially decomposed and fully clothed body was found June 16. The identity was confirmed later by comparison of dental records. Magdalena Davila, an organizer of the fund-raiser and sister of the dead man, said proceeds now will be used to investigate her brother’s death. A native Guatemalan, Davila had lived in the San Francisco Bay Area for 25 years.